Cryogenic treatment of drill bits: tested 2X lifetime and microstructure analysis

[@ThisOldTony]

great video as always... answered a few questions I've always had. They laughed at me when I told them my drills were being cryogenically frozen with me.

[@xMalhardeshmukh]

I heard you loaned your time lathe to Ben to get his DeLorean from the future

[@Derp0Army]

We need a collab

[@_BangDroid_]

@Grant Craig This Old Ben ... Kenobi

[@durlydurl]

Funny, as I was watching this vid, I thought "This Old Tony would love this information." Thanks for crossing that off my list.

[@samvimes1083]

ToT approved? I already know I'll like this.

[@davross600]

I liked the part where you DECLARED THE RESULTS AT THE START OF THE VIDEO. Truly applied science.

[@corey8704]

Half the fun is finding out what he had to improvise to complete the project.

[@Lisa_Minci96]

It feels that much more sincere that way, not that I had any doubts

[@NapoleonGelignite]

It’s a video abstract.

[@Don.Challenger]

But that is like any situation where you are the producer/director (réalisateur in French/realizer) the movie can end anyway you want - unless like our good man here, Applied Science (Ben Krasnow), you are essentially scrupulous in your execution. And why all experimental science requires calibration to standards and verification by replication (statistically and by method and design). Here he is actually reproducing known results as a personal verification for his own wider understanding of the process and we gain as a fortunate byproduct.

[@davross600]

Don't get me wrong, I still enjoyed watching the whole video! I just enjoyed it more not having to worry about waiting/looking for the results.

[@RFC3514]

I suspect the Venn diagram of people with DeLoreans and people with electron microscopes is a single circle.

[@Ritefita]

hahaha true story =) any owner of a DeLorean keeps few electron microscopes next to the doom devices box )))

[@jttech44]

Wait, you mean to tell me that they don't come as a combo deal from the factory?

[@JohnFrumFromAmerica]

I suspect Doc would have had a electron microscope

[@hakont.4960]

It is a popular car among eccentric scientists.

[@RFC3514]

And people who pronounce "gigawatt" correctly. After all, it's the same root as "gigantic", a giant isn't a guy-ant (it's almost the exact opposite).

[@sixtyfiveford]

Tempering and hardening of only certain parts is a common practice. So just putting the tip of the drill bit into the nitrogen to allow it to get as hard as possible but allowing the shaft to remain softer/less brittle.

[@nottelling6598]

It's a slow process inside an insulated space. While I'm not _sure,_ it wouldn't surprise me at _all_ if the bit was thermally conductive enough for this to not matter all that much.

[@JohnnyBuxton]

The rare occasion that 'just the tip' is preferable :)

[@henkholdingastate]

If this is so good I wonder how you recognize with a drill treated in this way and where you buy this cunt

[@skivvy3565]

🤔

[@Bob_Adkins]

Back in the day, I was a project engineer for my Fortune 500 facility. We drilled holes from .187 to .625, at 1-2 diameters depth. Finish, roundness, and straightness were super critical, measured in .0001. We used carbide bits, which were very expensive. One day an engineer from Cleveland Bits popped in, asking us to test a new gold TiN coating process. I must have measured 10K holes, and found TiN coating improved our drill life about 25%. It's worthless on all but precision, high production jobs on rock rigid equipment. But,,, all your tools, chemicals, processes, and lingo are very familiar to me. Enjoyed it!

[@kendokaaa]

You have a DeLorean. I didn't think I could like this channel any more than I already do

[@Amipotsophspond]

one day on this channel we are going to see a video on how he converted it to a time machine.

[@Amipotsophspond]

Doc Emmett Brown levels of cool, at this point.

[@PACstove]

@@Amipotsophspond If we talk about star gate portals, he'll start tinkering and figure one out. Lets push star gates around here for awhile and see what happens.

[@ErulianADRaghath]

He also has a tesla I think. So cool cars for a cool person.

[@joppepeelen]

im not into cars at all, but a delorean :) love em !

[@PracticalEngineeringChannel]

Haha showing off all the cool tools in this one. Very interesting!

[@gravelbar]

Has a DeLorean. Doesn't have a collet wrench.

[@SalvusGratiumFidem]

How awesome to just have a scanning electron microscope sitting around

[@skivvy3565]

Fancy seein you here. Now where’s machine thinking and the gang

[@captainpugwash4100]

This video took me back almost 50 years to when I started my apprenticeship in a metallurgy lab. The first thing I did for the first three months was to learn to polish micro samples. I must admit that your first attempts weren't bad, but here are a couple of tips for anybody wanting to try it out for themselves. 1. Put the abrasive papers on a glass plate with plenty of water, even better angle the glass plate and let the water run down the abrasive papers. 2. Hold the specimen so that all the grinding marks run in one direction and when moving to the next paper turn the specimen through 90° and grind until all previous grinding marks have been removed. This will give you a better start when you start polishing on cloths with diamond paste. The last time I visited a met lab, it's all done on machines these days, it used to be an art but has now been lost.

[@EricStuyvesant]

It's still an art, even with machines, in my experience. Back in the late '80s through the '90s, when I was last practicing, I had access to machines but in most cases preferred to prepare the samples by hand. It was easier to monitor/adjust through the process when working by hand, and there was less cross-contamination of grits. There was typically a perfect consistency for the higher-grit abrasive slurries (I only rarely used diamond, alumina was better for my usual samples) on the cloth, and you could tell by feel as you were holding the sample, and adjust with water or more slurry to maintain that perfect balance between material removal and buffing action. But I was only preparing at most a couple dozen samples per day. The machines had a tendency to over-remove material/over-polish, and many of my samples I was trying to wind up on a specific cross-sectional plane, so again, easier by hand. All that said, your advice on preparation is sound.

[@captainpugwash4100]

@@EricStuyvesant I have spent the last 25-30 years working as a 3rd Party/Vendor Inspector. This has meant visits to Metlabs to witness Tensile, Impact and Hardness testing and occasionally looking at micro specimens. I can't honestly remember the last time I saw a facility capable of producing specimens by hand. Occasionally I have asked the staff whether they could produce specimens manually, the overwhelming answer was "No". And this why I call it a "lost art". The true mastery of this art is to get scratch-free specimens, right to the edge. In the late 70s, I did a fill-in job for a couple months, training an ex-welder to prepare micros but preparing the difficult ones myself. This lab did make production micros, but also micros on defective boiler walls, which required totally scratch free samples because the edges of the sample were the critical areas being examined. So considering that most boiler walls were scaly rust coated (which constantly broke off when you really didn't need it), at after etching, Nital seeping out between the rust scale and metal to discolour the micro, because the microscope light was emitting so much heat. Mounting these in epoxy only made the situation worse. We tried an ultrasonic bath, but then the solvent leaked out under the microscope. All I can say finally, is that it took a long time to train this guy up to the standard required.

[@TTheHuman]

@@captainpugwash4100 I dont work in a metlab but abour 3 meters from one. And they still do alot of specimens by hand, especially the finish.

[@Oscar4u69]

met... lab? FBI, OPEN UP!!!

[@joewboe]

@@captainpugwash4100 What I do for samples with cracks or pores is take compressed air and gently blow the samples surface from a low angel and it helps to get the fluid out of the pores. Even then though you run the risk of fluids in the cracks. The worst is when the enchant seeps out of the cracks or pores and over etches the sample. I wish someone would come up with a way to get a two part epoxy with one component that seeps in and then you just have the co-reactant seal up the pores on the surface

[@victoryfirst2878]

This is something that years ago I have done myself before all the hype of cold treatment. I used max cobalt alloy drills and end mills. The process which took about three days really improved the life expectancy of the tooling. About 3 to 5 times to be exact. What got to me was how quickly the manufacturer caught on to the process. Do not totally understand the process but the process worked for me. This is similar to hardening HSS bits in liquid mercury which today is a big no no. You go through close to a dozen drill bits until you have one that survives, the rest explode into a cloud of dust. VERY DANGEROUS STUFF FOR SURE. ENCLOSURE A MUST FOR SAFETY. Nice work Sir too.

[@charlespax]

Hey! I made that temperature data logger! :-)

[@Ariccio123]

Such a small world!

[@skivvy3565]

And we thank you for your efforts. Thanks bud

[@NickHorvath]

"I hope I answered questions you've had for a long time, too." Ben, you answer questions most of us never even knew to ask. But I'm super glad you do.

[@robot_spider]

"I happen to have a DeLorean" **huh, interesting** "I happen to have a liquid nitrogen generator" **mild irritation and jealousy** "I happen to have a scanning electron microscope" **rage quit... also subscribe.**

[@mythicanomaly3079]

with 500k subs u can buy free cnc machine's too not to forget

[@SDWNJ]

Ben’s nerd flexing on us.

[@_BangDroid_]

"I have a scanning electron microscope" 🤯

[@blahorgaslisk7763]

@@_BangDroid_ That's a pickup line I've never tried. Mostly because I don't have a scanning electron microscope...

[@realityhurts8697]

Spoiled bastard, my wife wont even let me use my plasma cutter in the garage I have to do it outside

[@derekpeterson8005]

I make custom knives and I can tell you the difference is night and day in edge retention. Great video showing the microscopic effects of the cryogenic process. Thanks for sharing your time and talent!

[@sheriffoftiltover]

I don't even do anything related to CNC or metallurgy and I watched the whole video. You're very good at keeping viewers engaged. Very interesting video.

[@JerryBiehler]

If you spindle has a VFD on it there is often an analog out line that is programmable to do something like a 0-10v signal based on current. You could monitor this for spindle load and get a more accurate result of what you would consider worn out. You could also chart this per hole and see of there is a trend over the life.

[@OEFarredondo]

Genius

[@18magicMARKer]

wow real science, real test, real experiment, real reference to primary sources! impressive...which more youtuber did this

[@Asdayasman]

Thought Emporium NileRed Wendover Productions AvE ElectroBOOM bigclivedotcom The Engineer Guy Clickspring The good youtubers are out there, you just need to find them.

[@ironcito1101]

@@Asdayasman The Engineer Guy and Wendover are great but they don't do tests or experiments, they explain things. I can add Kurzgesagt to that list. Others, like Veritasium and Technology Connections, also mostly show and tell, but they occasionally do some tests. I'll have to check the others you mentioned.

[@JohnMeacham]

@@ironcito1101 They are more product/process oriented, but if you like no nonsense scientific/quantitative reviews CNC Kitchen is great for 3d printing and Project Farm is fantastic for shop tools/automotive.

[@e-rambler4910]

Smarter Every Day

[@CKOD]

You could have totally gone with "Double drill bit life with one SIMPLE trick" and a thumbnail with a red circle on something and totally gotten away with it. Also, for polishing fiber optic polishing film may come in handy. You can get aluminum oxide (cheap, $0.50/sheet sort of range) down to 0.05um, and get a good optical finish on most things. Maybe not fully diffraction limited, but you sure wont see the scratches. Diamond film comes down to 0.5um, and is a little less reasonably priced, but will polish whatever you want to use it on.

[@aerobyrdable]

@अल्ली X He actually put out a video about that, and how he didn't do this for a living, so didn't care to get caught up in the clickbaity game. All the respect to Mr. Krasnow.

[@nagualdesign]

Gotta love those red circles. ⭕

[@WrinkleRelease]

The joke Ben made in one episode showing what a AS clickbait thumbnail would look like still makes me chuckle.

[@unintentionallydramatic]

👀👀👀👀👀👀 Fiber optic polishing film, huh.

[@deus_ex_machina_]

Not necessarily, Ali. Such clickbait would either attract amateur handymen, or those who want a quick fix for everything. Neither group are likely to become interested in the topic, whereas the scientifically inclined might be put off by clickbait.

[@otm646]

The trick for your mounts is to use material of a similar hardness in the epoxy. Steel BBs are often used in industry.

[@jimquinn]

Just throw three steel nuts into the epoxy as outriggers. That will level the epoxy mount's wear.

[@joewboe]

A phenolic resin is what is most used in Industry

[@JimQuinn11794]

Sorry to disagree, but I have imaged hundreds of epoxy mounts in the SEM, and still do presently. Buehler's EpoThin and Struer's Specifix-20 are the most common. Allied High Tech's EpoSet is next. There are others. The low-viscosity epoxies take longer to cure, but offer excellent penetration and "edge retention". You do not get this from any of the "hot mount" materials, including the phenolics. All of the hots outgas incredibly in the vacuum of the SEM. The speed of the hot mounts does not surpass the quality of the expoxies. My two cents...

[@snuffying]

@@JimQuinn11794 mhm, i know some of these words

[@daviddaddy]

@@JimQuinn11794 Are you an alien??? Because i understood bassically um "my 2 cents" lol

[@BM-jy6cb]

I love this channel! The guy's got his own electron microscope and today he casually tells us he's got a Delorean, but what he's interested in is the cryo-treated door mech. What more can i say? 🙂

[@aceroadholder2185]

Years ago I worked at Champion Aviation as a manufacturing engineer. We drilled a lot of Hastalloy and Inconel. The drills were purchased from Germany and then sent to a grind shop in Ohio for a special grind on the cutting edges. After that the drills were sent to cryogenic treatment. As I recall, the drills were cycled through the treatment several times to get the best result. We got about twice the life out of a drill that had the cryogenic treatment and about triple the life of a drill that had neither the cryogenic treatment or special grind. Even with all that, drilling a 3/8" diameter hole 2.5" deep was slow going and the performance of the drills had to be closely monitored.

[@StrangeParts]

Cool to see you using the Pax Instruments logger. I hung out with Charles Pax in Shenzhen while he was developing it. It's a pretty slick piece of kit, but I haven't seen many people using them.

[@tafsirnahian669]

no reply, why not :-)

[@Rushil69420]

“But lucky for us, I have a scanning electron microscope...” I was already impressed by the liquid nitrogen machine god damn

[@thorwaldjohanson2526]

When I heard that I was like:.. O_o WAT?

[@mrjodoe]

yes dude, I also thought I need a liquid nitrogen machine...ma so jealous now :D

[@toolguyslayer1]

Liquid nitrogen machine for your beer perfect size almost

[@HERGRYN]

@@lewisavinash1 And only 150W oO

[@Ariccio123]

My favorite part about this channel, following for like ten years, is always something like this

[@FelonyVideos]

"I have a delorean... I have a cryo cooler... I have a SEM..." I have nothing but jealousy!

[@Shaun.Stephens]

Yep. If I had half of his 'toys' I'd be making youtube videos also.

[@comancheclub3449]

For real. The hits just kept coming all video long. Insert WWE Vince McMahon meme.

[@afrocatpro]

He gets so excited when he starts talking about his scanning electron microscope

[@mitseraffej5812]

I’d settle for his ability to keep his workshop tidy.

[@madscientistshusta]

Ikr

[@reyramos66]

Great video! I'm a Mechanical Engineer and it's being 25 years since I took my Metallurgy classes 😁, and you have reminded me all the classes. Your explanation was right on and simple. Excellent!

[@rfariavitor]

That comparison you made between cement/rocks and steel/carbide precipitates was just amazing. Thank you for this awesome content.

[@Ritefita]

thats true. I loved my mathereology lessons so much! but I never understand the sense of "solid solution of carbon in iron" so clear like now with this cement.

[@rfariavitor]

@@Ritefita Indeed! I'm an engineer and this comparison never came to my mind.

[@AttilaAsztalos]

"...luckily, I have a Hadron Collider in my basement, right between the Gravitational Wave Detector's tunnels and the Neutrino Detector's cave, so I took a few shots of the Higgs..."

[@77.88.]

LOL

[@f.d.6675]

😄 close, very close

[@unitedspacepirates9075]

FYI Interferene of your Haddon Collider distorts neutrino count data squared to the distance

[@PetCactusA_HarmlessLittlePrick]

I took a few shots of Ardbeg.

[@NaterNorris]

I'll just pull out my portable fusion reactor for this test. Lol

[@ReasonMakes]

So excited to watch this but before I do just wanted to thank you for the consistency amazing content you make for us all :) Every video is to the point and about the subject matter. Pure science. Thanks!!

[@TitiMiscione]

amazing video, I really hooked up into this one because of my metallurgical engineering degree. About the temper after the cryo treatment paper thingy. Basically, tool steels are meant to be hard, wear resistant and tough (so it doesn't break under service), that is controlled by the carbon content and carbide precipitation. The more carbide, the harder the steel, but the tougher phase is the martensite, relatively speaking. And the higher the carbon content in martensite, the lower the toughness of the steel. HSS tools are actually tempered 2 to 3 times in order to fully temper the structure and reduce the brittle newly created martensite by carbide precipitation. The paper's author hypothesis would be that the newly fresh martensite formed at cryo temperatures would be of high carbon content and would need to be annealed. Not sure how good that hypothesis is tho, since carbon diffusion is really higher than the other elements (Cr, V, Mo).

[@tubester4567]

...and thats why you dont see cryo treatment used for professional applications. The advantages vs the cost doesnt make sense. If you need harder than HSS , theres carbide, and a few other HSS treaments which is much quicker and cheaper to make.

[@LakshmananLM]

@@tubester4567 used for gages.

[@xenonram]

I've always been confused about the ability of HSS to be treated red hot when grinding it to form, without it losing its temper or hardness. Why is that?

[@davidb6576]

@@xenonram Remember that the term "HSS" encompasses a whole range of tool steels. Some have higher heat tolerance than others, but getting a HSS to true "red hot" is generally going to cost it some hardness. It's the alloy constituents and treatment that determine how much heat it will take before property degradation.

[@tubester4567]

@@xenonram Most grinding operations of HSS involve coolant. Even if you're sharpening a drill by hand you need to keep it cool as possible by dipping it in coolant. HSS does lose some hardness when it gets hot, as has been said. Most professional machines that use HSS cutters have coolant running to keep everything cool.

[@trebushett2079]

I started sub-zero treating steel about 40 years ago. This was specifically to convert the case retained austenite in EN36 carburized steel, to martensite. Without sub-zero treatment, hardness values were in the region of RC58, and after subzero treatment in the region of RC62. Apparently, nickel-chrome carburizing steels are prone to retained austenite in the case, after harden, refine and temper; whereas case-hardening mild steels such as EN32 will easily harden up to RC62-63 without having to resort to sub-zero treatment.

[@stanbondarev9256]

Hi Ben. I strongly recommend to etch the sample of HSS steel in Nitale for at least 5 minutes, and then try 15...20 minutes of whole etching time. WIth SEM you will see the microstructure with more details without problems like on LOM. You've shown us a matrix with carbides, but martensites grains were still unetched. So the difference is present but unclear as for me. Anyway -- very good project! Thank you,

[@PapiSmerf]

I have found companies selling cryo bits taken to the point that they are so brittle you just can't use them in anything outside of a very expensive CnC machine. Anything but precise ins and outs with perfectly controlled speeds and they shatter like glass. They also last forever.

[@GStarGoku3]

The compactness of presentation really stands out in these videos. Super high quality content.

[@jamiekawabata7101]

"Luckily for me, I have a time machine." - Ben Krasnow

[@ДавідЦінделіані]

"Say, Professor McGonagall, did you know that time-reversed ordinary matter looks just like antimatter? Why yes it does! Did you know that one kilogram of antimatter encountering one kilogram of matter will annihilate in an explosion equivalent to 43 million tons of TNT? Do you realise that I myself weigh 41 kilograms and that the resulting blast would leave A GIANT SMOKING CRATER WHERE THERE USED TO BE SCOTLAND?"

[@corey8704]

Today on Applied Science we'll be retrofitting a Delorean with a portable fusion device.

[@drrrrockzo]

I tested some cryogenic drill bits in my machine shop and at first I was really impressed...but in the end I couldn't justify the additional cost over standard M42 ("cobalt" HSS) bits. We manly work with 304 and 316L (stainless) and initially the cryo tools seemed great...but we discovered that they were fairly brittle. The worst was when they lost their edge...I've been hand sharpening drills for nearly 20yrs and every time I touched up a cryo drill they shattered on the first hole. If I had to guess, I would say that the heat of regrinding them created extreme stresses in the metal. It was a mixed bag, when new they cut stainless like a hot knife in butter. Their main drawback is that it seems like they need to be cryo treated anytime they were sharpened.

[@rickr7333]

So I'm an old geyser (62) but cryo treated metal is very old now! It initially started with the treatment of engine blocks for cars, it was called seasoning. The cast iron blocks were left in the cold over the winter and then left to heat in the summer for a "season" (discovered in the late 1940s). It was found to increase the strength of the metal. This video shows the benefit of taking a metal down to a much lower temperature to make it even stronger by letting the crystals homogenize. This technique was perfected in the late 1980s when metallugists discovered what this video misses that multiple temperature cycles will make a metal (and potentially anything) stronger by an order of magnitude. That process requires that the metal is both taken to a hardening temperature then taken down to a cryogenic temperature multiple times. Then after several cycle that produce a fine grain metal, a tempering process is performed to draw down the hardness to a usable level.

[@louf7178]

Interesting. You've got 18 more years before "geezer".

[@discopoe]

Hi Ben! Thank you very much for this interesting video, it was a real joy to watch! Also seeing someone having his personal SEM in his work shop was amazing! :-D While I heard about cryo-treatment before, I never really touched the literature about it until now. To be straight forward, I am pretty sure there is no generally accepted reason why cryo-treatment seems to work that well. The explanation often given in literature is the one you also used. Converting retained austenite to martensite increases hardness and thereby tool performance. While I could not find the precise high speed steel used for these bits on the manufacturers page you linked, their heat treatment is basically always the same. After hardening they are all tempered to increase the toughness of martensite AND transform retained austenite to martensite. Hence, after the typical heat treatment, there shouldn't be any retained austenite left. Consequently, the transformation of retained austenite to martensite cannot be the cause of the observed performance increase. You also mentioned that the procedure worked despite the fact that these bits were heat treated some while ago. This also points away from the presented explanation, since retained austenite is in fact thermodynamically stabilized by carbon that diffuses into it after quenching. However, maybe the cryogenic temperature reaches below the stabilized austenite's Mf temperature. Some more comments: By tempering high speed steels, their martensitic phase does not become softer that much, due to the precipitation of secondary hardening carbides (typically Mo2C and VC). The higher alloyed tool steels, such as HSS, might even increase in terms of hardness, depending on tempering temperature and duration. Practical tempering of HSS does also not include the formation of pearlite in the microstructure, but the transformation of retained austenite to martensite, reducing martensite tetragonality (increases toughness), and precipitation of secondary hardening carbides. These secondary hardening carbides are in the range of some nm and hence significantly contribute to the hardness of the materials by precipitation hardening. The carbides you observed via SEM are much larger primary or proeutectoid carbides which are designed into the steels for tribological reasons. However, those large carbides do not significantly contribute to the overall hardness or strength of the steel. The difference in the former austenite grain boundaries (in which the martensite laths form) look like etching artifact to me. But could also be a valid difference between the samples. If you want to check for that possibility you would just need to polish some more samples and analyze whether this difference between treated and untreated samples appear continuously. Finally I'd like to mention again that I really enjoyed your video. However, as a material scientist I just could not help myself but comment on some details. All the best, Joe

[@brendant1272]

Great comment. I was looking for someone with some sense in the comments. I can't find anything explaining the true mechanism behind this but I would love to hear if you have discovered anything

[@GemAppleTom]

Hello Joe. Slight correction on what is otherwise a very well written comment: Even triple tempering of some HSS grades will still leave you with some retained austenite. It'll go down certainly but not disappear altogether. (I too noticed the steel grade wasn't mentioned on that link let alone the thermal history so we can only speculate what the content is for those bits) Deep cryogenic treatment has a poor history alas. There were wild claims from industry and a load of absolute dross published in the 1990s which gave the whole thing a bad reputation as snake oil. Most of the benefits come down to full transformation martensite which doesn't take 20 odd hours to achieve. There are hints that in some steels (but not others) you do see benefits like finer and more evenly dispersed carbides. Though as you say the mechanism isn't understood. We'd need a cold stage TEM and careful machining to investigate properly and to the best of my knowledge no one has done that yet.

[@discopoe]

@@GemAppleTom Hello Tom, thanks for your comment. I agree with you, I should have been more precise on the matter of retained austenite content. Some time ago, we investigated the retained austenite content of HSS after quenching and tempering via synchrotron XRD. While we were able to clearly identify austenite peaks, austenite content was negligible. I'd love to give you the precise numbers, but I simply do not remember them. But yes, none at all is not correct. With regard to your comment on dispersion and size of the secondary carbides. I could certainly imagine that the cryo treatment overall causes a higher dislocation density in the martensite formed at cryogenic temperature as compared to the martensite formed from retained austenite at tempering temperature. Higher dislocation density means a higher number of potential heterogeneous nucleation sites for the carbides. However, that's just a qualitative statement of course. Best, Joe

[@ericmichel3857]

We have been cryo treating automotive racing parts (brake rotors, gears, bearings...) for many years and they benefits have been well proven. They also show that it essentially doubles the life of many high wearing components. Cryo treated brake rotors are very common. Great demonstration, thanks.

[@GemAppleTom]

Hello Eric. Do you leave the parts at low temp for a long time (24+ hours) or just a couple of hours?

[@circlecitycryogenics4584]

We have had great success cryogenically treat different components also. Rotors, tooling and gun barrels the most.

[@aivkara]

Dang, I'm consistently stunned at the amazing quality of your videos. I learn every day that there are even more things that I know nothing about, but man is it a pleasure to learn with you. Hats off to you Ben!

[@lazyh-online4839]

In terms of toughness vs hardness, they aren't always mutually exclusive. It would be interesting to see what happens if you increase the hardness by cryotreating then tempering to the same hardness as untreated bits, I guarantee that the toughness will still be higher. Partially this is due to the more consistent grain structure, I'm not very good at explaining it but basically the unconverted martensite acts as weak points and when you finish converting the martensite then the sum of toughness and hardness increases overall because you remove those weak points. Edit: if my memory is correct I believe the unconverted martensite is actually called retained austenite, as it's austenite that hasn't been fully converted to martensite during quench.

[@rwnelson51]

Amazing science, demos and more!! One personal observation: for me as I'm a bit "auditory delayed ADHD" type, Ben's presentation clarity and especially his tempo or meter is so engaging. In this nutty fast-paced world your presentation dynamics are the best!! I'm reminded that my best professors in school had this unique ability to use the pause, tone of voice and again tempo which garners greater attention, retention and frankly great enjoyment!! Well done on many levels!!!

[@electronicsNmore]

Fantastic video! For years I used a thermos for liquid nitrogen. It works fine as long as you leave the cap loose to vent gas.

[@tafsirnahian669]

fontastik

[@garbleduser]

I wish you did an audio frequency test before and after. Ring the bit like a bell.

[@eugenew2]

Analyzing the waveforms could possibly tell contaminants, hardness, damage of the material.

[@e4Bc4Qf3Qf7]

Science is awesome

[@kranganekar]

ohhh resonance check... god damm never thought of that .. !!!

[@xenonram]

You're on to something, but ringing the bit wouldn't tell you much that is definitive. However, analyzing the sound while it is drilling can give a more consistent EOL point.

[@rvsteve583]

@@e4Bc4Qf3Qf7 yes it is!

[@cls63amgwagon34]

HAHA quirks and features! We’ve got a Doug watcher here!!

hahaaaa,,,yep

[@markg6160]

My exact thought.

[@ddegn]

I'm apparently out of the loop. Who is Doug? (I'm going to regret asking since I already watch way too much KZbin.)

[@albertlagerman]

@@ddegn Doug Demuro. He reviews cars.

[@ddegn]

@@albertlagermanI've watched a few of Doug's videos but I haven't watched enough of them to recognize a commonly used phrase. Thanks for letting me which Doug was being referenced.

[@wims58ej]

I did a test of a high end HSS , non cryo treated brand of drill bits against their cryo treated bits in 304L stainless steel plate. 304 will ruin drill bits very quickly. The difference was very amazing. The cryo bits just seem to keep drilling forever and the non treated bits failed pretty fast. I was not trying to ruin them quickly by drilling aggressively as in this video.The drill salesman was also shocked . He asked me to do the test again so he could take a video of it. We switched to the treated bits and I have used nothing else since then. I hardly ever have to resharpen a drill bit .

[@kknives_switzerland]

Yup, same here, I cryo treat not only the knives I make, but all my tooling. I found it even works on carbide tooling! (There are also some very interesting studies on cryo treatment of carbide.)

[@johnvreede832]

I can confirm that a solution of alcohol and nitric acid does react, in the end violently. I burned out the inside of a fume cupboard and acid-burnt the parquet floor of my lab. I was trying to recover the silver from spent Brashears's silvering solution (had silvered the inside of a giant (36"x6"dia) vacuum flask (like a Thermos bottle) for an experimental setup for my MSc). I had poured conc. nitric acid into the spent solution which had a small amount (4ml/L) of ethanol in it as a wetting agent and about the same amount of cane sugar (also reducing agent). It fizzed a bit, from the diluting of conc acid, then didn't seem to do much, so I poured in more acid. Still nothing seemed to be happening so I went for a coffee break and came back to fire engines and excited onlookers. The reaction starts real slow, so slowly it looks like nothing is happening, but then gets faster and faster and gives off LOTS of heat and brown NO2 gas. It bubbled, then foamed and eventually ignited. In a closed container I expect it could explode from the pressure of the NO2. This happened with just 0.4% alcohol solution (and admittedly LOTS of nitric acid). I would not leave any solution of alcohol and nitric acid in any container and walk away. Dilute it right out and dispose of it, don't store it - jv

[@rootvalue]

May I just say I appreciate the quality of your audio? The lav (or otherwise) mic you use for live shots is killer.

[@JosephAlukka]

I think he has an external preamp with auto gain control, audio almost never reaches the clipping limits.

[@frostrap]

I’m going to start giving my drill bits a Doug score.

[@danapatelzick594]

This was very interesting. The continued conversion to martensite at cryogenic temperatures is well predicted with metallurgy theory. I have treated aluminum using a similar cryogenic process with the end objective of making the aluminum more stable so it retains its shape or flatness over time. Weirdly enough it works and I don't know why. I have never found an explanation in metallurgy theory. I looked about 15 years ago and found a few papers where they were using this process on telescope parts (University of Arizona). Have you ever looked as something like this? I have left this behind because of a different job where high precision aluminum parts is no longer a requirement but every once in a while I'm reminded..

[@rodschmidt8952]

Work-hardening? Creating a tangle of screw dislocations? I mean it contracts and then expands

[@joewboe]

If its wrought aluminum it is probably precipitation hardening. Age hardenable aluminum precipitates copper even at room temperature. Thats why high end aluminum castings and wrought parts sit for a couple weeks to let them age

[@TheLtVoss]

Mhm Duraluminum and its process is about 100 years old so I would say the information was even 1990 public available you just used the wrong search method or you didn't stumbled across sertain keywords properly because you thought of harding with a matrix shift like in steel but aluminium and its hex matrix doesn't do that

[@SolidRockMachineShopInc]

We started using the Cryogenic process on DC53 and CPM3V setup tools we make and you can definitely tell the difference in the grinding. I had to change to a ceramic mix wheel to hold under .0001" tolerances in 5". We did a few KZbin videos on these talking a little bit about the Cryogenics process. So far they seem very stable as well. I love the benefits of Cryogenics. Thanks for the excellent video. Steve

[@duodot]

I absolutely love the way you explain things. Enough detail to keep someone familiar with the subject engaged, but not so much that it bewilders those with less prior knowledge. I wish I could explain things like you do. Keep em coming and have a splendid day!

[@j.rumbleseed]

Tempering improves the Austinite to Martinsite transition. That is the simple part. The other part is the de-hydrogenation of the steel through the grain boundry area. You did a great job here that's for sure. I've been doing cryo treatment for over 12 years now using a CPI 500 cryo system, and there is much to report.

[@mikafoxx2717]

Yeah, I've been reading knife steel nerd's articles and it does a good job explaining this. Retained austenite isn't great for performance, and tempered martensite at the same hardness will certainly outperform it. Just don't over-temper into martensite enbrittlement. Cryo seems most effective immediately after quenching, even a cold freezer will net half the effect of liquid nitrogen, and even liquid nitrogen loses some effectiveness after an hour thanks to austenite stabilization. Cryo still works after tempering, but not as effectively.

[@martingrundy5475]

Fabulous content, as usual. Bravo indeed. I can barely believe that was seventeen mins. It flashed by so fast it felt like barely half that time. Superb.

[@sonovoxx]

Same. I thought I'd skipped a bit, so watched it twice!! True story!

[@mikeissweet]

If it makes it harder and more brittle, how is this a good application for the torsion bar?

[@ipissed]

Maybe because it's stainless, DeLorean wanted everything stainless and it's the closest way to make stainless like a spring steel.

[@TheMetalButcher]

Upping it's yield strength I suppose so that the fatigue life is extended if I had to guess.

[@hunakosdem]

Yeah, how about your topic raiser question, Ben? 😃

[@ottopike6000]

It only has to be flexible enough. After that it's only decreasing the plasticity of the steel, which decreases the formation of stress concentratons.

[@Scrogan]

Torsion bars aren’t typically subject to sudden shocks, I can’t see an issue with it. Spring steels are usually hardened as it makes them more resistant to plastic deformation and gives them a higher spring constant.

[@AlanLangford]

Your content is amazing. More noteworthy, you have one of very few channels on KZbin where the comments are numerous and also not a cesspool of stupid / hate / negativity. There should be an award for that.

[@igneous061]

....damn, so a guy basicly makes experiment by every single scientific standard....talks over everything, provides many citations and details....omg, you are miracle

[@willybee3056]

I saw program about cryogenic treatment. It said that it works on everything from pantyhose, ballpoint pens, music instruments, rifle barrels, ect. ... This was years ago... Thanks for sharing your videos.

[@bradley3549]

Ben is just checking all the boxes on this video. Delorean. Cryo. Electron Microscope.

[@Garganzuul]

And high metal removal rate. Don't forget the metal removal rate.

[@theeddies]

That is absolutely fascinating all around. For one, I would have never considered that the martensite process could just be continued after months or years long normalization. I learned about 4 things here that I never knew or even considered about steel. Further, I create as well but can only imagine the time and effort put into a test like this. The only cryogenic process on metal I was ever familiar with was treating guitar strings (Blue Steel brand, which I have always used). I had never considered why it works so well to bring out brighter sound, now I have to find out. Great stuff as always. Thanks!

[@ElizabethGreene]

The "aging" process isn't unique to steels. Aluminum and cast iron castings machine entirely differently fresh cast vs. letting them sit on a shelf for a year.

[@theeddies]

@@ElizabethGreene That is very interesting.

[@smacknives754]

I finally got to try this out, I put a couple of cheap quality drill bits into LN2 overnight, and today they easily drilled through 1/4'' 5160 spring steel, which had just chewed out a couple of untreated drill bits, I was blown away how well they worked, so much so, I've just given better quality drill bits a cryo bath, with the intention of doing all my HSS bits, curious if HSS-Co would be advantaged too??. Thanks for the awesome experiment, Scott.

[@michaelmechex]

You have just taught me more about metallurgy than endless amount of metallurgy lessons at school. Thank You.

[@MrRolnicek]

I think this might be the only channel on KZbin where it MAY be possible to recreate the carbohydrate (direct carbon) fuel cells and even play with the technology (maybe even improve on it considering how young it is). I would REALLY like to see that.

[@kaylor87]

"Quarks and features" - shout out to Doug!! Also, I did not know you owned a DeLorean! My gawd, that thing is gorgeous! Coolness factor just went up so much

[@knartfocker00]

I was hoping you'd break some to test the change in toughness. Great video, as always! 👍

[@gregwarner3753]

A long time ago I tried this in a high school lab with a dry ice (frozen CO2) and acetone mixture. Tested the drill in a metal shop drill press. Did not find enough difference to make it worth while. My HS science teachers indulged me. It was better than going home early.

[@CucumbersSC]

First of all, what a fun video! What a dream to have your own SEM. But I'm a materials engineer with a focus on steel, not much more than a student but I still have some things to add that I didn't see in the comments: tempered maternsite =/= pearlite! Pearlite is a nice lamellar eutecticum of ferrite iron and a carbide called cementite, and bainite is the same phases in a fine, kind of... messier, eutecticum. Eutecticum is a structure, the beautiful "woodgrain" structure you see in metallography images sometimes, and it's the lamellar structure that gives the "pearly" fracture surface referenced in the name. The carbides in tempered martensite may be the same as the cementite (Fe3C) phase in pearlite but can also be other carbides. They are very very finely dispersed, like nano-scale, approximately spherical, but can of course grow with further treatment. The tempering after cryo-treatment absolutely does make sense if that finely dispersed carbide structure is what you are after, otherwise it is most likely the final little bit of martensite will remain in its glass-hard state, with the BCT atomic structure. I didn't watch your video on hardening so I don't know how familiar you are with the finer points of that, but tempering is what allows the carbon atoms to come out of the BCT lattice and form carbides, with high C-affinity metals like Cr and V and with Fe as well as that's the base metal. I would guess the large carbides you see are of chromium or smt rather than iron, the carbides in tempered martensite are typically even smaller. Although I can't interpret the images with certainty, because as much as I love martensite (who doesn't) I have primarily studies the stuff that happens in melt phase, and also like... no scale bar and just a youtube vid etc, haha! Anyway, if anyone read that I hope it added something and that it hadn't been said before. I really enjoyed this video and love seeing people discover what an incredible effect the microstructure of steel has on its properties!

[@djvanzz]

Love when SEM is used in a video

[@grndragon2443]

I've wondered about cryo treated engine blocks. Would be interesting to see how much longer they last vs non treated.

[@JakeWitmer]

If at all. They might just crack right away

[@chir0pter]

@@JakeWitmer wrong, cryo treating is a common process in racing

[@sasjadevries]

I would like to see how much it really alters the hardness. A 3 point bend test and some hardness test is what would make the video complete. Then we could at least get a feeling of how much the drill life is improved due to hardening and how much due to structural change.

[@1SweetPete]

Damn, now I want to see that...

[@measl]

*I just found you by accident, and I am in awe! Your garage was my basement before fire destroyed it. I'm a biology / biochem freak, but we seem to have very similar kinds of fevers! I LOVE this! Definite new sub, and I plan to start with your first video and work my way back to the present. Thank you! This is better than going back to school (at 67, I don't know how I'd handle that)!*

[@Gunth0r]

KZbin really needs to stop disabling these bells, I'm 100% sure I hit the bell already for this channel.

[@whiteflag2366]

Lucky me, I have a machine that makes nitrogen liquid on demand ... That was cool!

[@kNasty_]

This is fascinating, but I cant help but feel like it brought up more questions than it answered. Why would the delorians torsion bar door spring want to be super hard? I Would expect it to become extremely brittle and snap in half upon first use. Also with the drill bits tested, what was the failure mode? Dulling? Tip breakage? What other physical properties changed? Do they sound different when struck? Do they transfer heat or electricity differently? Does one bounce more when dropped? How many of the failures can be attributed to overheating which may have change the metalurgical properties. -both in the treated and untreated bits. It would be interesting to see the crystal structure of the area the did the cutting before and after use compared to the same from an untreated bit. Maybe even analyse the same steel through other heat treat processes for points of comparison as opposed to the mild steel you showed. Annealed and normalized, quenched, and tempered to compare against the cryo and whatever processes the factory used. All that said, I understand it would be a second big chunk of work to go through just to answer some guy on the internet's curiosity, and couldn't reasonably expect - or ask- you to go through all that trouble just for me. At any rate, Keep up the good work, your vids are certainly some of the best and most interesting around.

[@mikee4402]

The material in the Delorean is not the same as the drill bit. the Delorean rod is likely a martensitic type stainless or high alloy steel where as the drill bit is tool steel, The structure shown for the bit did not look like martensite - it just seems to show a more uniform dispersal of the carbides ( but it might look different if his optical scope was more powerful or if the sample was etched with a different acid) So when forming a martensitic structure as in the torsion bar -(for strength and durability) there is a chance for forming undesirable retained austenite (weak constituent). To eliminate this the bars are cryogenically processed. Those bars would also be tempered to reduce brittle failure

[@a.i.privilege1233]

"I just happened to have a cryocooler" Things mad scientists say.

[@petermarsh4993]

Dear Ben, thanks for your excellent description of the science around cryogenic treatment of metals. I’m curious about your sources for the various ex-laboratory equipment that you happen to have laying about. My trips to the recycle centre produce some used planter pots and a very rusty old plane. Your collection is amazing. I can only imagine what you and your mates got up to in sleep-overs when you were a teenager - making all kinds of fascinating gadgets. I think that you are the first KZbin presenter that used a double-blind trial to help prove a theory about cryogenic hardening. You are also the first that searches the literature for verification of your results, not just arrogantly saying that they are correct because you did them yourself. Well done.

[@theosky7162]

Finally a reason for the LN2 build project. All my CNC bits will now get this treatment. Long term expecting ROI to be worth it. Thanks!

[@Mycon]

Your videos are always amazing. You're a real modern time Renaissance man, Kudos.

[@inspectorsteve2287]

I got a good laugh out of the "if you don't have a cryo cooler" comment. Lol. Very cool video

[@tcb9775]

"Heaven forbid" 😁

[@GRBtutorials]

Yeah, since Ben's video these are now very expensive (though Ben also got lucky), so "magical unobtainium" as tesla500 said.

[@snitkofb]

"I hope this answers questions that you've had for a long time, too." I guess 17 minutes is a long time, atomically speaking.

[@thetruthexperiment]

You really do answer questions I’ve had my whole life in every video.

[@Pogohontas.]

Your channel is my favorite science related channel, and it keeps my passion for such things alive!

[@rafaellastracom6411]

You miss one important issue. The point of cryo treating steel is to convert retained austenite (RA) into fresh martensite. Fresh martensite cannot be put into service without tempering, just to brittle. As such the tempering cycle would have eliminating the majority of crack initiaion sites which in turn reduces crack propagation rates. That would have increased your fatigue life i.e. how many holes you can drill. You achieved a 100% (double) increase in number of holes drilled. If you repeat the experiment with cryo+tempering you will most likely see a 400% (4 times) increase over none treated bits. One more thing, retained austenite in a martensitic structure is a function of carbon content. The more carbon the more RA. As such these findings are only true for high carbon steels. From 0.60% carbon on up this phenomena is observed with ever increasing effectiveness as carbon content increases. Below 0.60% carbon you will gain nothing with hypo-eutectoid steels actually seeing decreases in fatigue strength.

[@DCFusor]

I'd bet that the edge temperatures almost instantly reached in "pushing it" drilling - as he mentioned - quickly accomplish tempering sometime near the start on the first hole. I do machining, and the edges, where it counts - even with various forced coolant modes - get quite hot - even incandescent - fast. He's using high speed steel here that's meant to not "lose it" at red heat. As he mentioned, there are other carbide-formers in that alloy - the iron has to "share" and doesn't even get all the carbon in the mix.

[@gmack4097]

Wouldn't that greatly exceed the performance of M42 and even tungsten carbide?

[@Jessassin]

"One of its many weird quirks and features" Someone else watches Doug 🤔

[@JayMadyal]

I came down to the comments to search if there's someone like me who could catch that phrase! "Quirks and Features" 😅

[@saintclearance926]

"🤔" 🤣🤣

[@clownhands]

THIS is my 1983 DMC DeLorean...

[@benkirkland5354]

“Lucky for us, I have a scanning electron microscope” ... ultimate flex

[@moeszyslack4676]

Incredible video. Makes sense why Lie-Nielsen has the blades of their planes cryogenically treated. Thanks for this awesome test and video.

[@mwblades6553]

I really liked this a lot. I am a knife maker, and if you go to knife making forums, you will find argument, after argument of people going back and forth on the "effectiveness" or lack thereof depending on the steel, the temp needed, or some understanding of what it is doing. The microscope and pictures really brought it home for me. It would be interesting to see what it does to different types of steels. Specifically if high carbon steel (52100, 1095, etc.) would benefit, or if only super steels of the stainless verity are the only ones that require the treatment to achieve full potential. thanks for the video.

[@bowieinc]

Great video! I came away with one question. Why does the cryogenic process take 20 hours as opposed to 15 or 25 hours? What is happening or continuing to happen to the drill bit’s structure beyond the moment it reaches the lowest temperature? Thanks!

[@brucewilson77]

I would like to see this test done with taps !!

[@timorii]

The holes are already there 😎

[@peterfitzpatrick7032]

@@timorii sooo.... 1/4" hole is the tapping size for ? M7 X 0.75p seems close enough ?? 😎👍☘🍺

[@xenonram]

5/16"-18

[@la24dogg21]

Its easy just hold it at liquid nitrogen temperatures for 30 something hours

[@cybotx1024]

The most mind blowing part of this video isn't the visible results of the cryogenics but how casually he manages flex real hard. Video gets a thumbs up

[@BushCampingTools]

You have the "best toys" Love that cryo cooler. I used to have a smaller scanner , even smaller than that one of yours. Drove around to rural schools showing schools kids in the country all sorts of stuff in an SEM, we had modified it of course so it would pump down very faster without using a diffusion pump but by a turbo pump system. Great experiment! Great video!

[@DrTimmay]

Still watching so maybe you answer this, but how does it affect the dimensional tolerances?

[@billsimpson604]

Probably not enough to be anywhere near the normal tolerance with which the drill bit comes from the factory.

[@Xmara01]

It makes it more stable overtime .

[@matman7546]

The drill would likely grow slightly. Perhaps 0.001” per inch of diameter at a maximum. The cryogenic treatment transforms any retained austenite into martensite, and the phase change into martensite comes with volumetric growth. Conventional drills do not produce accurate bores anyways, so it is inconsequential. For precise bores, a drill is used only for removing the bulk of the material. The bore will be drilled undersize by a prescribed amount, then reamed or bored to size.

[@alext9067]

360 Excellent point. Very astute.

[@geekswithfeet9137]

Spindle amps/ slip would be a much better metric

[@peterfitzpatrick7032]

Heh... just posted the same thing behind ya... "great" (🙄😏) minds think alike !! A clampmeter on the phase wire... 3 phase maybe a little more complicated... but deffo a more objective way of detecting drill bit wear & subsequent load increase... 😎👍☘🍺

[@xenonram]

@@peterfitzpatrick7032 the CNC controller will already output this metric. You can set it to alarm out if spindle load reaches a certain point. (Not sure if his machine will do it or not.) So he could set it to drill hills until spindle load gets to a certain point, then it'll stop.

[@rionmotley2514]

Ooh. Power factor.

[@GAIS414]

Not sure what the curve would look like though. Probably medium amps for starters, going up as the cutting edge dulls, and then going back down again past the starting point as the drill bit dulls to the point where it stops cutting and starts chirping. Instead I would suggest a temperature measurement of the tip of the drill bit directly after each completed hole. With pauses in between holes to normalize the temprature of the work piece and drill bit. The curve would likely be more consistent than measuring amps to the spindle.

[@rionmotley2514]

@@GAIS414 I bet there's enough meat in the flutes, and clearance for chips, to put in a little thermocouple... *ponders drilling a drill bit*

[@MGoat76]

Best line from the video: “....but lucky for us, I happened to have a scanning electron microscope.” 😂

[@jasongreene303]

Thanks for The vijeo, Ben! It's good to see you again. Cool topic once again, I'm never let down!

[@samcalaz8531]

I think this is very cool, but what I like the most about this is the fact that you linked the relevant research too.

[@7177YT]

Has got a Delorian (wait what?) mentions it in passing. while talking drillbits ...cause u know, it's a closely related subject. Well done Sir hehe. (:

[@anomie4477]

7177 he talked about it in one of his videos before more than once I think

[@7177YT]

@@anomie4477 new to the channel, but here to stay Cheers!

[@bbrown6799]

I’ve been interested in cryo treatment for a while now, so I really enjoyed this video. I want to build a LN2 generator, but I can’t find the cold head you used and I don’t know enough about how to power it. A more in-depth how-to in your build process would certainly be appreciated!

[@JustaReadingguy]

So is the drill bit failure do in part to increasing the temperature and annealing the steel to the softer form? And would that explain why the slower drill speeds last so much longer?

[@turningpoint6643]

Adding heat will start to soften anything. The recommended industrial cutting speeds in feet or meters per minute are at best a compromise for tool life against the metal removal rates. Adding flood coolant keeps the cutting edges cooler. That either gives you longer tool life at the same rpm or increased production from running faster with the same cutting edge life. It depends on what will gain or lose the most money on which direction you would go. Dropping the cutting speeds by say 10% does not give you 10% longer cutting tool life. It could be 30%-50% longer. So those recommended cutting speeds are only a guideline for the maximums you shouldn't exceed. Or you won't if tool life is at all important.

[@HealthCarePC]

Pretty good job investigating the effects on Cryo treatment on drill bits. I'd correct one thing. The tempering after the cryo treatment is for structure change to "tempered martensite" and not pearlite as you indicated. The newly formed untempered martentensite done by continuing the quenching of the steel is very hard and brittle, so by tempering you're adding ductility to the steel and losing very little hardness. Depending on the class of High Speed Steel (M2, M4. M50 etc...) tempering post treatment usually starts at 900*F to precipitate secondary carbides from the Molybdenum or Tungsten (in other steels) and is done at that temperature to anticipate the heat that drill bits will be subjected to in normal service. One of the risks of not tempering post treatment is upon use, the product will temper in service and therefore be unknown as to what the final property is because it's in the users hands and not the heat treater. Nice job on the etching too. Nitol is the standard etchant and you got some pretty good pics considering your setup.

[@lsdave]

One of the most under rated channels on KZbin.