Machining & Heat Treat Tool Steel Vise Inserts! WW128

[@SpencerWebb]

When you do the hardness testing, make sure your automatic center punch is perpendicular to the surface. It will read low if it its at an angle.

[@WobblycogsUk]

I'm no engineer but I used to be a chemist... to stop scale build up on the heat treat they probably use an inert atmosphere. Any of the noble gases would work well, my guess is they would use argon as it's fairly cheap and readily available. You could probably rig up an inert atmosphere in your kiln by just drilling a hole in the side, inserting a pipe and connecting it to a bottle of argon welding gas. They almost certainly wouldn't use a vacuum to stop scaling, maintaining a vacuum over the sort of temperature cycle the kiln goes through would be tough and it would reduce the efficiency of the kiln as it would mean heat could only really transfer via radiation. Thanks for the great videos, you're teaching me a lot about CNC.

[@WobblycogsUk]

Glad I could help. I used to run a large furnace under these conditions (chemists call it a reducing atmosphere because it lacks oxygen). Assuming your door has a reasonable seal the flow rate you need to maintain an inert atmosphere is really low, much lower than for welding. You can can get high temperature ceramic tube which would last a longer than a steel tube and might be useful for resting pieces on while heat treating to keep them off the bottom of the furnace.

[@MauledByBears]

Boric acid also helps reduce scale and it's cheap. Jewelers use it all the time.

[@daigriff89]

Vacuum furnaces are widely used in industry. we use them for aircraft parts. they are certainly not cheap... or desk sized!

[@northernmetalworker]

When we were heat treating a2 tool steel, which is very sensitive to scaling. We wrapped our parts in stainless foil with paper inside and heated them. The off gassing of the burning paper creates a carbon atmosphere around the part, simple, effective, affordable.

[@WobblycogsUk]

@daigriff89 Do you know why the parts are heated under vacuum? As you say it's an expensive way to make something hot so I'm guessing it must be doing something to the metal other than just preventing scale build up. I wonder if it's to remove any gasses dissolved in the metal, in particular hydrogen.

[@Stephen1455]

We used to use the tool wrap, wrapped airtight with piece of newspaper, never done it before, results were perfect!!!

[@stanstocker8858]

Hi John. Wrap in iron wire and coat with borax mixed with alcohol to avoid scale. You can also try coating the material with soft soap, works well too. W1 and O1 are pretty forgiving, in parts this size you could hold in a small iron wire basket and borax, hit with a torch until a magnet doesn't stick, and quench. Easy as can be. Polish up real quick on your scotchbrite wheel and heat until the parts get a pale yellow/straw if you want really hard but still tempered. I just plop batches in the kitchen over wrapped up in aluminum foil, take the oven to 450 or so, and after an hour turn it off. Next morning you have nice uniformly tempered parts. Punches I differentially temper, blue well back from the face, pale yellow on the face. You can polish to a mirror finish without being easy to chip. Have fun, you will be amazed at how darn easy it is to make all sorts of tools. A2 is even better, no quench needed and just a minor temper.

[@makun16]

Clickspring on his channel offered great advice for dealing with scale which I have used to great effect on O1. He coats the parts in boric acid mixed with mineral spirits (makes applying it to your work easier). Once the parts are tempered, place them in boiling water to dissolve the boric acid coating. If done right, no scale and it's more cost effective than foil.

[@eformance]

Wow, that hardness tester is about 3 times the price of what I would expect it to be. $875 is way rich for the level of precision it offers.

[@EVguru]

I've oil quenched W1 to avoid cracking on parts with sharp inside corners. You won't be able to achieve as much ultimate hardness, but it usually doesn't matter. To help reduce scale, but a piece of charcoal in the oven to consume the oxygen. A chalk paste helps too.

[@terrykishbaugh7699]

The stuff you filed off on your O1 is the decarb layer that occurs when the part is exposed to high temp in the presence of oxygen, decarburization occurs and the carbon in the metal comes to the surface. You can use stop off paints to control this with the temps that O1 and W1 are heat treated at.

[@Z287899]

Another couple options for the scale is a paste type carb block, heatbath makes some. That just washes right off after heat treat. Another option is a diamond block which is a cool insert you put in your furnace that creates an ideal atmosphere for heat treating.

[@davidrahn9903]

Hey John. While I don't have experience machining o1 or w1 I have experience forging both and from a heat treating standpoint o1 is so simple and forgiving in a heat treat that it's almost funny. While you can get into the super nitty gritty with heat treating, especially with modern alloys and mono steels, generally speaking o1 is just get it hot and dunk it oil and then draw the temper back with a touch, w1 is much more finicky with the temper in my experience. But that's just my 2 cents. Thanks for the video, it was fun as always.

[@bcbloc02]

65RC is extremely hard for tempered tool steels. You are at almost as quenched like you didn't even do a temper. You should likely raise your temper temp to get more in the 60RC range for service. Foil wrap works well for avoiding the scale but is a bit of a hassle. Depending on how air tight your oven is if it is pretty air tight you can throw in some newspaper to burn up and deplete the chamber of oxygen, thus avoiding the scale. I hear the stuff ATP makes is the best and easiest to use. I would put a link here but then the comment would be invisible spam.

[@occamssawzall3486]

bcbloc02 The numbers did seem pretty high. I was expecting to see mid 50's after tempering.

[@occamssawzall3486]

NYC CNC Re-temper? Not sure. You can anneal it back to soft state, then re harden and temper. Though. In theory your should be able to temper at any point after hardening. I can't think of a good reason why you couldn't

[@bcbloc02]

You can temper or temper further(higher temp) at any time after hardening. Obviously if you over shoot and go too soft then you have to re-quench but one of the beauties of high carbon steel is how easily it is worked.

[@kmcwhq]

John, you should explore the idea of acquiring a used Hardinge HC "Hand Chucker" lathe. With 5C collets, and an 8 position turret, you could pop those round parts in a collet and break the edges with a nice chamfer, etc. Very handy for many uses around the shop, even cutting off cap screws, etc. A great machine to have for general 2nd operation work, prototyping, making washers, spacers, etc. Handy, and quick for simple tasks!

[@muellermaxwell]

we use conversational where i work and its the way we just give the conversational program a program number that coresponds to the part number.. so when we run that job again we just look at the part number, type it into the machine and theres the program. also theres a place where we put setup notes and a note describing each tool.

[@BasementShopGuy]

For your window, my friend and i were talking about (his) too. You can machine a channel and slide in 1/8" thick glass. If it gets scratched, insert a new one.

[@johnferguson7235]

You could try using some window film to protect against shattering. It's amazing how tough the stuff is.

[@Boosted98gsx]

Wrapping it in some kind of wire and using boric acid (being held to the part by the wire) will help create an anti-oxidizing layer during the heat. Check the channel "Clickspring" for some DIY heat treat DIY ideas!

[@302mck7]

foil bags do help,at work we also make purge box's with sand seals. also when checking parts make sure area tested is clean of scale.

[@TheRealFrankWizza]

The foil bags will help, and will help even more if you put in some paper or sawdust or whatever to burn up and absorb whatever 02 is in the bag.

[@EdgePrecision]

John, I'm not sure with that hardness tester but having the part on the paper towel when you make the impression might change the reading. particularly as your parts are so small and light in weight. Doesn't John Grimsmo use foil to heat treat his blades? You could ask him.

[@einars899]

Yes, it will be almost worthless. It should be on a heavy hard piece. And with a compound between the test item and the heavy backup.

[@phantomlord71usa]

as a tip we've made it a rule within our shop to not only write on the side of the rod with a paint marker/sharpie what the material is, but also metal stamp both ends with 1/8 or 1/4 metal stampers. The problem was guys in the shop would often forget to write on the material what it was, or it got rubbed/smeared off. So we'd end up with mystery material. We'd also designate only 1 person for sawing and give them the responsibility of cataloging and indexing material. Which corrected a lot of bad habits of just any one in the shop grabbing material and running to the saw to whack off a piece, and not document or even return the remainder back to the storage rack. We've got a lot of general purpose 1018/1020 CR, but we also got some really high dollar high tensile material in stock for special purposes. And just on appearance they look very similar.

[@cnc-ua]

hey, John, thanks for the video. just my 5cents - hardness tester should be used on a tough plate, probable even with well fixed part. Otherwise it will lie a lot. By using soft material you rise up readings. Actual hardness definitely lower because of that. Difference could be up to 15RC

[@Somun-a]

I did not actually check the specs of the tool steel rods but I think that its safer to assume that they are not round enough for precision work.

[@099bmac]

I had a great machine shop teacher, (can you tell how old i am, ha), anyways he was a heat treat god and would tell you what color to heat to , when and what to quench in. I learned a lot from this guy.

[@alexhorne4189]

Oil quenching is a slower and less violent process than water quenching. Water quenching can sometimes cause warping, distortion and stress buildup because of the air "pockets" that can form like you mentioned in your video.

[@MorganOliff]

Hey man thanks for taking the time to grab a video at this cool stage of starting and investigating a project. Nice of you to have us along. Also the results weren't too shabby either. :)

[@tinkermouse-scottrussell3738]

Powdered boric acid you can usually get from the hardware store as a roach bait. Mix it with denatured alcohol to form a thick paste. Place part in a SS container and liberally coat the part to be heated, with enough of the mixture to ensure that it will cover the part once molten. Once the mix melts, it forms a protective glaze over the part, almost completely eliminating oxidation. Once quench is complete, wash off the boric acid residue with boiling water. One of the most effective heat treating oxidation protection there is for the home shop.

[@Wrenchmonkey1]

Thank you SO MUCH for showing me how to set the start line! I didn't realize that was an option, so I've just been re-running code with an empty spindle (if it's just a few brief ops), or just going back into the office and re-posting the code starting with the operation that I had to stop the code from. Such a simple thing that I didn't even know to search for! You're the man!

[@eviltsi99]

apply rainx windsheild treatment to the inside of your lathe window/mill window to help with visibility.

[@alexscarbro796]

I was wondering if a couple of "air blade" style structures could be used inside your lathe window to deflect coolant away from it. Perhaps with one blowing and one sucking so you don't create lots of turbulent air inside the machine....

[@SacoreyRugger]

on the lathe window, you could run a plate of hard glass inside to resist scratching and a polycarbonate outside to protect against anything coming through the viewport into your face

[@OldePhart]

beadblasting cabinets have a peelable cover that might help you.

[@cornchips9693]

Love you John; please be careful with those galvanized all thread and nuts. Fumes!

[@JOHNPHUFNAGEL]

I used to work at a heat forming and treating co. 20 years ago so I don't remember what the hardness number are but We used a Rockwell and a brinell tester and did 3 test on each piece then calculated the average. If I remember correctly the brinell higher the number the softer and the Rockwell the higher the number the softer, I maybe wrong. Anyhow very cool John

[@Eggsr2bcrushed]

A wild notification appears! Enjoy your Wednesday John!

[@63256325N]

Are you able to speed up the feed rates, if you will, when the tool is not in contact with the workpiece? Know what I mean? For instance, when the chamfer tool was moving into position, it was moving so slowly, I guess the air time before contact, can it be sped up? Or would that be too much of a pain to program? Thanks for the videos.

[@hockeygeek21]

I actually just ran a Heat treat cycle of A2, D2, and O1 today on furnace similar to yours but on a bigger scale, I absolutely despise heat treating O1 just because it is so messy, but it is so much cheaper. Would rather do W1 because its not as messy, but in the stamping industry its not quite as durable as the other tool steels and seems to be more brittle. A2 and D2 are both air hardening material, which makes it very simple, but requires temps above 1700*. A2 and D2 are usually where the stainless foil comes into play. Heat treat requires a lot of time and patients, something I have very little to spare at the moment! LOL!

[@honel440]

For smaller ovens like that, a charcoal briquette works well to remove some oxygen out of the oven, and if you keep it in a tray you don't have to worry with ash getting on your parts if you're beyond auto ignition of something like paper or wood. Just be aware that when you use something like that to consume the oxygen, the gasses in the oven may be flammable and above ignition temperature when you open the door. Not a terribly large flame, but it will take some arm hair if you're too slow....

[@Sketch1994]

I think what you want is some A2(air hardening). As also mentioned by Dan Gelbart(check him out) the only tool steel you need to stock is A2 cause it is the easiest to harden and also due to the slow cooling it deforms the least from the heat treatment and you can do almost net size before grinding.

[@JustinAlexanderBell]

Have you tried an ultrasonic cleaner to remove scale?

[@barrygerbracht5077]

Nice job on the heat treat. Interesting that they were both very similar in hardness afterwards. I don't know if these are actual grips or just tests, but don't you want a little relief on the edge so the grip grabs at the top edge, even if only by 1 degree or perhaps a few 0.001 undercut? Even small deflections will make the grip grab at the bottom edge increasing the risk of pop out I think. You don't want a grip where even small amounts of movement will cause them to loosen.

[@austincassell4741]

you could try spraying some rainx on the lathe window so you can see more

[@vegandiver]

you should probably balance the load in your vise by clamping an equivalent part in the other side or use the center of the jaws, but it seemed to work. I'd definitely do that for square stock though.

[@CharlesGallo]

125 degs F can be touched -the reflex pullback temp is about 140

[@SacoreyRugger]

Charles Gallo any idea what the clamp reflex temp is? because I definitely caught a 700°f stainless rod bare hand and while my mind was screaming "drop it you fool" my hand said no and all I could do was scream profanity

[@NateUE]

If you use a stainless foil bag you can add a little carbon to the bag to soak up any oxygen. Something like a small piece of paper would work. When you pull out the bag, cut it open to let the part fall into the quench.

[@rafaellastracom6411]

Keep in mind the Martensite Start (Ms) temperature of the Steel. For high carbon steels like W1 and O1 the Ms is around room temperature, and in some cases below. If you begin to temper when the material is at or above this temperature the Steel will not fully harden. Maybe only getting 64 HRC instead of 68-69 HRC. The problem is that the retained austenite will, over time and use, convert to Martensite. Martensite occupies more volume than other phases and will literally grow. So that today the part has a diameter of 1.0000¨ but after a month it wil mysteriousy grow to 1.0005¨. That is why many old-time tool and die makers would set heat treated materials aside for months or more before final grinding. This is not a big deal for most components BUT if a customer asks you for a set of gauge blocks that must be to less than a tenth it becomes a serious issue. Food for thought. Before I forget, if you do not have SS wrap you can use a little piece of wood or a stick and throw it into the oven. It will smoke, naturally, but that smoke is carbon and it will help with decarburization. In essence you would be carburizing the part slightly but it would help keep scaling down.

[@Stephen1455]

Yes we had a top and bottom furnace, but not that expensive I think?

[@shaneharvey1026]

John, what is the material just under the clamps you're using to hold your vice to the table? Purpose?

[@christopherscott6435]

I would find an auto glass shop that cuts glass and get them to cut a laminated safety glass window for it, you could then put a hand crank or power windshield wiper like they make for jeeps on it.

[@michaelmurray3422]

Now that was really cool. I like seeing how things are tested and with the right equipment, prove that it worked. I mostly work with electronics, and do the same kind of testing to make sure it works like I designed it. But this is really cool to watch. I saw the vid's on the scraping, you all went to, and that too was really interesting to see. Looks like you all had a good time too. Have a good week, and I'm looking forward to what you have next.

[@JPapaPhotography]

Another fantastic video. Can't thank you enough for all you do John. I truly appreciate all the time you take out of your day to help us. Joe

[@wktodd]

thread the insert and relieve the screw below the head so the screw is captive in the insert

[@BasementShopGuy]

Ha! I have the same oven. Haven't done the burn out yet and I've owned it for over a year now, sigh...

[@mbeck2663]

John, love the videos. Long time fan. When measuring out the salt for your brine an easy way to get a more precise measurement is with a refractometer often used by saltwater aquarium owners. Keep the amount of liquid static and then you can determine the amount of salt per water valiume for a perfect mix.

[@Z287899]

Or even easier, float a potato! No joke. At the right brine solution a potato will float.

[@HughesEarthworks]

Really cool, John. I look forward to seeing some footage using the inserts.

[@DStrayCat69]

Awesome video :-) I am very familiar with "Brinell hardness testing". When I was a kid, I worked for "Reid Tool". We made Drill Steel for drilling Oil Wells... The Tool Joints had to have very specific hardness. Moreover, they could not have any Cracks... Where I worked, in the Heat Treating department, one had to be very careful about the Temperatures of the ovens, the Oil baths and a whole lot more... If there are cracks in a joint, it could mean catastrophic failure during drilling. For that, we used Magnaflux. Even passing the harness test, a Joint could fail, if there were cracks... Having said that, I think the parts you are heat treating and their end use, may not require crack detection or that sort of thing... When it comes to the Brinell Hardness Testing, you are using, I cannot imagine it being very accurate at all... We used a sort of "Press" to bring down the punch and when it reached a specific weight, it released, leaving a small but consistent dimple in the work piece... Consistency in the dimple size is paramount... We used a similar measuring glass, but the creation of a consistant dimple is far more important... Without a consistent Dimple, the eye-piece is useless... I'm sure you're aware of that... Anyway, good luck :-)

[@scienceaddict77]

Maybe try using rainex on the inside of the lathe window, to deter the coolant streaking.

[@rafaellastracom6411]

That is actually a really good idea. It would probably work well. Nice.

[@vernonkarm8016]

Rainex is not good for plex or lexan. It will cloud the surface of the plastic.

[@rafaellastracom6411]

I'm going to call you.... Buzz Killington IV. LOL

[@donaldmoore8023]

Oil based coolants also strip it off and hurt the coolant/sump life. Totally tried this once, which is how I know. Worked great for about 3 hours...

[@TheDandyMann]

If you're concerned about scale you could use a mixture of denatured alcohol and borax and coat the parts in the solution.

[@2222e100]

Similar to what clickspring uses.

[@Eggsr2bcrushed]

Clicksprings clock omg so beautiful.

[@Robbievigil]

CoolPatroler it's borax? awesome I just bought some for experiments for my.kids

[@NateUE]

Using borax is generally bad for the kiln floor. It eats right through some refractories. I don't recommend it.

[@ThePanndemic]

You could probably add a hydrophobic coating on your glass, keep it clean even while getting sprayed.

[@coastalintegrated]

W1 is water quenching but the tempering is really fussy with multiple high temps above 1000F. O1 is super low rech and forgiving in comparison.

[@markrainford1219]

Is it OK to centre punch on soft kitchen towel, won't this absorb part of the energy and give false highs?

[@WireWeHere]

Thanks for the book tip. A bit of lit paper can reduce your O² before you fire up your oven, if it's airtight enough Lots of ways to make it happen.

[@RobertSzasz]

Jim Marriott you don't even have to light it, and throwing a sheet of ceramic kiln paper on the floor of the kiln might help protect it

[@ginoo722]

Just a thought, You could set up a magnetic cleaning cloth like they use on fish tanks/bowls. At least you could try to clean up the window without touching it through this method.

[@GeofDumas]

Do you do any semi-automated finishing like tumbling?

[@Eggerd]

Regarding your comment at the 1:50 mark about the window on your machine, have you tried applying a rain-x water repellent? I assume it's some sort of poly carbonate and they do make one specifically for that, might help the coolant bead off.

[@Eggerd]

Interesting, hadn't thought about issues with mixing with the coolant but that makes sense.

[@DRrandomman22]

hurco has a fairly large memory and you save the job as the part number or something that identifies the part

[@DRrandomman22]

You can throw it on a thumb drive and move it from machine to machine yea you can't move hurco program to a mazake quick but I work in a hurco dominant shop. We're a job shop so it's so fast it crazy from raw stock to finish part the conversational is super powerfull. Yea we have to do cam for 3d work but if your confident in your point to point programing you can do alot more what you might think. but yea haas all the way for cam software because hurco cost your literally pay more for the controller than probably an equally capable machine from anywhere else

[@sickboymech92]

Give some thought to sand blasting window covers after you replace that window. Then when one gets roughed up just replace it and save the window. Or a tampered safety glass might work.

[@886014]

Good one John! I would have expected your parts to grow slightly after heat treatment, I'm surprised they didn't. The finish you're liking from the fly cutter is as a result of the insert, and not the fact a fly cutter is holding it. I can't recall what you have in regard insert mills, but if you're not getting similar results I'd look at what inserts you have in them. I know I've mentioned them to you before, but especially now with the new machine have a look at some Kyocera cermet inserts. Do some research about running them, but basically hard and FAST! They would have been ideal on that tool steel. Every time you mention the view through the lathe's window I think a SMW "clearview" window can't be too far away ;) I'd think a piece of polycarbonate from Home Depot and a 1000 rpm motor could see a Wednesday widget Clearview emerge. I'll disclose that I've never tried it and only seen the commercial units, but can't imagine it would be too big a job to make one.

[@1a3b5c7d8e]

You should get some air curtains for your windows when filming with coolant on!

[@sethjohnson3240]

Nice Video. I see your electrical load centers in the back. I am wondering if you have surge protection? It is something I would recommend as a voltage surge could completely ruin your CNC equipment. I know from experience.

[@chiefmachining7972]

Why didn't you just drill the hole in the lathe? Was the hole off center or something?

[@ello-mz6om]

Can you do a solid works tutorial? or why you only use fusion 360?

[@SupremeRuleroftheWorld]

put a small pipe in the oven and feed argon (you have that) in it. that will remove the air and prevent scaling.

[@gixxer1237]

foil bag it. will reduce the scale a lot. you could also coat it with a anti scale compound.

[@vespadano1979]

When you write on a piece of stock with a sharpie, stick some clear tape over it so it doesn't rub off from being handled.

[@christopheronstott2358]

You can use hss drills on D2,A2,S7,4140,4140HT and even in stainless !! Just use the right feeds and speeds and your good to go!!

[@marioprzepiora]

What tool did you use for engraving the numbers?

[@flyfaen1]

Nice. You can harden crankpins doing that :D

[@henrikandersson1299]

65 HRC is really a high hardness. If the annealing temperature is too low, the material gets extremly brittle (as glas with no ductility). If annealing to 60 HRC, you loose some hardness but gain alot of toughness! Do some test pieces; heat treat, anneal, and try a DIY "Charpy V impact toughness test" It would make a great follow up video! Test the materials in: Delivery condition Hardened not annealed Hardened and annealed 60HRC The test shows if your heat treatment yields the wanted material properties (impact toughness -> ductility parameter)! //Henrik -Engineer

[@099bmac]

John, Where did you get your diamond drag tool? and that kind of -Z value do you use and speeds? Thank you, BMac

[@099bmac]

Thanks John!

[@Kondzio29]

You should not open the furnace when it is on. My friend is doing ceramics, and she said that it could damage the heater coils if they are exposed to the oxygen in air you let in

[@2222e100]

I was going to sleep. But now there is a new WW!

[@BerndFelsche]

little trick for removing "plugs" from blind bores, if the plugs have a hole, is to put compressed air down the​ hole of the plug. Take care because it might shoot out when you remove the air gun. p.s. apologies for the duplicate posts. tablet interface is often a bit dodgy but this is an extreme case!

[@TUTOROchainoilers]

maybe a vinegar bath will take the scale off?

[@johnferguson7235]

I assume that the salt solution is 10% by weight.

[@craigs5212]

John, nice video. Ebay search for a grocery scanner replacement glass (really scratch resistant) or possibly hack the glass from an old Iphone and attach it to the inside of the enclosure with some RTV. For the coolant on the glass -- this sounds like an Arduino project -- periodic air and water blasts of the filming window to keep it clean. I noticed you did the hardness punch on a paper towel, I wonder if the cushion of the towel has any effect on the punch mark. Thanks for the pallet -- it's really nice Craig

[@vernonkarm8016]

Off subject John: What happened to your new/used grinder? Saw a short video then it disappeared..

[@jkotka]

hi John, great video once again! looked like the hardware you used on the heat treating was zinc plated, you werent worried about the syanide it creates when heated?

[@TheToneGod]

Kind of OT but are you putting that spindle shutdown when changing ops but still have the same tool in the spindle in the code manually or is that the post processor ? I had the stock LinuxCNC post doing that and I corrected it to take those out. It just seems like a time waster. If it is the post I'm pretty sure I can tweak the post if you want. Andrew

[@TheToneGod]

Around 7:30 and 13:40 for example as you are switching from the roughing op to the finishing op the spindle shuts down then immediately starts up again. Are you putting that pause in or is that from the post processor ? I have seen this in other videos for awhile now and I have been wondering about it. I had the same issue and I modified the post to remove that shutdown. I also have a conditional in the post that when I set the spindle RPM to something low like 1 RPM to have the post remove the spindle start M3 completely. That might be useful for the engraver so you do not need to manually remove the M3. Andrew

[@charrontheboatman]

Gr8 Video as always man, love the heat treatment section, as with most of us a day late with my info but as a jeweler we heat treat just about everything we make in tooling just w1/o1 with a torch and a light soft flame temper...keep on making chips!!

[@jaredr2374]

I would think you cut those soft jaws with a corner radius end mill. Leaving a fillet at the bottom. And your perfect 90 degree corner of the tool steel didn't fit in the corner perfectly causing the bur to be raised.

[@waynep343]

meguiars plastx can be used to clean clear plastic really easily. use the palm of your hand including fingers to make it work.. you could also use a piece of leather or smooth soft vinyl .. what happens when you apply it with a cloth . all the super fine abrasive goes into the cloth. it won't go into your skin.. or thru shiny leather scraps or smooth vinyl upholstery material. try it on a small area lower right corner of the inside of your window if you can lift the whole door off.. do the lower left inside corner if you cannot remove the whole thing.. there are clear acrylic sprays to keep the surface from oxidizing again.. same as found in headlight polishing kits. some brands have fairly nasty chemicals you don't want to get on your hands. hint.. a half drop on the cell phone plastic surface covers wiped franticly with the finger tip.. not into the microphone or speaker restores the clean look.. its plastic polish.. also available in many other brands.. i just like the non chemical version of meguiers. want to polish a device on the lathe to mirror finish .. a drop or two and some leather. you might get some scrap and make a wooden spanner wrench shape to hold the strip of leather so its leather only.. no backing to push on the part . sorry for the wall of text.. my tooling is dull and it does not cut thru text as well.

[@dlstanf2]

why does everyone use a plastic bucket for quenching? why not a metal bucket?

[@TAWPTool]

Yet another very motivational video! Thanks for sharing John.

[@sirpacolour397]

Hair hello I need this one. How much can you please tell me

[@cncmachinist3111]

If you want a new window measure it, then go to any glass place and get some safety glass cut to size. It will never scratch and last for the life of the machine. All new HAAS machines come with safety glass instead of what they used to use which was just plexiglas or whatever. Old Cincinnati Milacrons came with safety glass and if you look at any auction for one of them their glass is still pristine.

[@tsw199756]

Check your tool steel material with a 3 point external micrometer to see how round it truly is. A conventional micrometer cannot check roundness as it is only a 2 point dimension. Centerless grinding does not always yield accurate roundness especially on off the shelf stock vs. say a dowel pin.

[@MikePalmer42]

I would not bother with the foil packet with O1 and W1 it is worth using anti scale compound you can get it from brownells gun making suppliers I use it when heat treating my knives

[@MikePalmer42]

www.brownells.com/gunsmith-tools-supplies/metal-prep-coloring/heat-treating-accessories/anti-scale-coating-prod23076.aspx

[@stuarthardy4626]

Mike Palmer Coat it in borax or silver soldering flux that contains borax Thame a look at clickspring you tube he demonstrates the principle parts come out scale free

[@MikePalmer42]

Stuart Hardy I did look into it but I find the antiscale compound is a easy way to do it and I have heard that the borax can affect the refectory in my oven

[@DELUS10NAL]

Great video John!

[@Malorie001]

No need to go directly to temper cycle. And borax will stop scale.

[@harrisonaero]

Suggest that you're too sloppy on your hardness test punch. Place on hard, flat surface and hold perpendicular for repeatable results (if it were me I would use your threading arm/machine to make it easy). Verify by using exact same technique on test block. $0.02

[@GeofDumas]

I wonder what happens, molecularly, if you wait to temper

[@NateUE]

Not much. Heat treating changes the crystal grain structure of the metal. A normalized(not hardened) metal has it's crystals arranged randomly making it easier to squish or scratch the surface. Hardening aligns the crystals making the structure much harder to squish or scratch but if you drop it prior to tempering it has a high risk of cracking the part. Tempering reduces the hardness and makes the metal tougher to crack.

[@GeofDumas]

so tempering might not need to be done immediately after hardening other than to minimize the risk of dropping the part?

[@NateUE]

Not necessary as in right that moment but generally sooner is better than later. Some geometries can crack due to their own internal stresses as they cool. It all depends on the shape of the part. Something simple with no inside corners like a knife can wait until your main kiln cools down to tempering temperatures.

[@hettinger1000]

Another interesting and informative video. Thanks John.