How to Harden Mild Steel? (Impossible!)

[@kobiroar4221]

Working in sandals, no gaurds on your grinders, work bench that looks like it could walk out the door. I'm impressed!!!

[@peterroper9090]

But yeah, make sure you wear your mask!

[@lyes6033]

if you look at my videos you can see me work with slippers but at the end of the winter they were busted and had to throw em away ;o;

[@finnvb8208]

It was up to the Swanson code

[@spoonforthought3534]

“Stable platform”

[@xgu4642]

Come with me and you’ll see a world of OSHA violations

[@scbane]

If you want to forge strong, flexible, no nonsense knives, forge them from leaf springs you get from the junkyard. Leaf springs are 5160, a superb forging steel, which is also easy to heat treat and temper, and has commonly known heat treating recipes. Be sure to forge the spring to shape with a hammer, that way any stress micro cracking are forge-welded.

[@kwader_1404]

good advice

[@deezgamesareforyou8926]

Although you are correct about 5160 being a great, forgiving, and easy for beginners with basic tools to work with not every leaf spring on the planet is 5160 steel, I recommend getting a set of hrc files and harden a test piece to see what it reaches, beginners without these files can do a simple spark test if the sparks are bright and have a firework effect its a good sign thst you've got a higher carbon steel on your hands, happy forging!!

[@OUTDOORS55]

That’s very interesting..you should try and grind out a quick bevel, sharpen it, and test a thinner edge. Funny thing is, I think most cheap “stainless steel kitchen knives” are made from the cheapest stainless they can get their hands on. The steel you have there will probably hold an edge better than most kitchen knives under $30.

[@marianogarabato1111]

If you used a wood or coke forge you are adding carbon (if steel is in cherry red or more the atoms of carbon can pass true the Fe). By the other hand seams like 1045 or close to that when you cut the piece, if is the case you can tampering this steel. If you work with mild steel you can add more carbon using 80% of charcoal and 20% of borax, you heat the piece to orange and let cool in this mix, more times you do more steel you get (each time is like 0.5mm deep of high carbon steel). I hope helps you. Best regards from Argentina and sorry for my rusty English haha

[@TitiMiscione]

it's the cheapest steel because it needs low chromium concentration to be able to harden through martensite transformation. it's not really intentional. the best stainless steels for hardening have low additions of other carbide forming elements (Mo, Ti and W), to decrease grain boundary corrosion. But they are still incredible cheap when compared to regular austenitic stainless steel.

[@kalcrow5194]

Out of ALL the videos I've watched on this subject, telling you to heat the steel to this or that degree this was by FAR the most comprehensible. Thanks 👍

[@simonp347]

Some thoughts after watching the video: 1, Structure steel also come with different grades, can be low or medium carbon. 2, Salt water has much higher cooling rate if you want higher as-quenched hardness. Temper as usual. 3, Easy way to do break test, is to grind a small notch (stress riser) on the test piece, put it notch nown on the anvil with something under one end, and hit the back side with a hammer. Hope it helps.

[@workwithnature]

Structural steel has sometimes more carbon in it. Rebar is any scrap they could find, so also may vary in carbon content.

[@tragikk03]

there is no such thing as "structural steel".... when I ordered raw material at the structural production fitting/welding shop, I couldn't just call them up and say I need 3'x3' structural steel angle iron....... I say I need 3"x3" angle, if I don't specify, they will send mild steel... Mild steel is what most structural applications use (unless corrosion is an issue and zinc coating won't work)

[@harrypehkonen]

Back in the day, I used to use an oxy/acetylene torch with a carburizing flame to put a thin wear-resistant coating onto the business-end of some gardening tools. From what I have seen, rebar is basically the shepherd's pie of steels -- it's made of left-overs, and you never know how it will behave outside of its intended use.

[@MegaBoilermaker]

The carburising process that you describe is still a legitimate means of local hardening of low carbon steels.

[@pyrotech1999-bootlegblades]

Very interesting video. When making little rebar knifes, I've always hardened and quenched them just for practice. Never really put them through much use. One test I think would be really cool for you to try with the mild steel knife, is called the "brass rod test." There are videos out on the interned about it, but basically, you push and slide the edge of your knife across a brass rod and if it bends and stays bent, its too soft, If the edge chips, its too hard. But if it flexes with the curve of the brass rod, then springs back into place, you are in good shape. Of course there are alot of factors that effect the outcome of the test, such as thickness of the edge, and the angle it is sharpened at, but you know you did something right if your knife passes the test.

[@suuris1]

Hello, I must thank you!!! I used an old drill bit to turn it to a mini lathe knife. On second try, I managed to harden it. It works great. Many thanks!

[@tylerburlingtonmachining7723]

FYI never have the sparks shooting away from you. It sounds counter productive, but if that zip disk grabs, that grinder is coming directly at you. Have fun, but play safe.

[@connorhart7597]

Learning about quadrants is borderline a necessity for using an angle grinder, like full stop

[@bagongpilipinas351]

He don't even know how to use the grinder🤣🤣

[@1959Berre]

About breathing protection: keep the mask on your face after you finished grinding indoors. The fumes and dust particles stay airborne longer than you'ld expect.

[@andrelarocque5967]

I'm not so much worried about the particles as I am the guardless angle grinder.

[@joesikkspac7904]

Guards are an obstruction. For a small wheel like that and at those low speeds, there isn't much danger. A catastrophic failure might break the skin. You have to hit 10k with heavier wheels to do damage. Stones are more dangerous. Much more so and you should do a ring test. I was a chipper and grinder at an iron Foundry for 8 years. I never once had an abrasive wheel, flanged cup stone or disc failure.

[@chrishayes5755]

@@joesikkspac7904 if that disk tears apart it's going straight into your eyeball. google images "angle grinder accident".

[@alanbrunner4116]

@@chrishayes5755 that's why you wear a full face mask

[@alanbrunner4116]

@@joesikkspac7904 exactly. And disk don't break just because. If they break its because the person did something wrong

[@jobean4]

@@chrishayes5755 read the maximum RPM on the grinder and the wheel and if the wheel doesnt exceed that then have a ball

[@me2bfc]

Structural steels will harden. They are generally either A36, A572, A500, or A992 ASTM grades. They aren't usually intended to be hardened, so it requires some different techniques and temperatures. Quench in as fast a quench as you can find. Icy salt water comes to mind. There are no elements in these steels to allow them to harden with slower quench baths like oil. Heat these steels to a higher temperature than normal. 1600 F is a good starting point and may require more. Lower carbon content raises the temperature needed to harden these steels when quenching. The magnet trick only tells you the temperature is above ~1425 F. Some high carbon steels like 1080, 1075, 1084, will harden below 1400 F, but you need very good temperature and time control to do it consistently.

[@TheHyde8875]

Dude. You have GOT to use the right side of the disc when cutting/grinding. That's how you grenade the disc. Start using the opposite side. Yes, it throw a the sparks in your direction, but if you have the right PPE on it's not a big deal. Definitely not as big a deal as blowing up a disc anyway. I learned the hard way, you don't have to lol.

[@ryankabcenel9700]

bingo oatmeal you've got no clue what you're talking about. It's not really which side of the disc you use, it depends on direction of travel. And REALLY even that doesn't matter, they'll blow up either way. Go witj American or German made and you should be fine. And that's why you always wear a face shield when cutting.

[@wanderingcalamity360]

I'd love an explanation of how a composite cutoff wheel can explode from rotating one way but not the other.

[@ryankabcenel9700]

@@wanderingcalamity360 you're talking to the op right?

[@wanderingcalamity360]

@@ryankabcenel9700 Yeah.

[@Robert-qm7yi]

@@wanderingcalamity360 Long story short, same reason chainsaws throw chips at you instead of away. Easier to control when it's pulling away, and when it grabs it pulls up and away instead of down and back, which is was safer

[@OperaBass3]

I suggest viewers look up in back copies of "Home Shop Machinist" for a couple articles I read there about this specific concept: that mild steel is unpardonable. My recollection of the writer"s conclusions is that mild steel is indeed hardenable to a limited degree varying with the carbon and manganese content, the cross section (thickness for practicale purposes,) and rapidity of the quench. My reading of the sparks in this video suggests to me the mystery metal may be a low alloy structural steel, not A36 structural steel at all. It might very well be suited for heavy duty chopping tools like brush hooks, froes, wedges, pick axes, cleavers etc where a strong tough edge is preferred over a hard edge where chipping might be a concern. It might be nice to learn the actual Rockwell C hardness of the test samples but that may not be necessary for back yard smithing. I suggest tests with a center punch struck with care for blow consistancy, and comparing impressions for depth etc as a means of comparative surface hardness. I also suggest you hacksaw, file, hand polish to a smooth matte finish with clean wet of dry sand paper all three of you samples to obtain a flat cross section unaffected by heat (as from grinding.) Etch the samples with phosphoric acid (NOT muriatic or sulfuric) until dark with etching smut. My preferred etchant is metal surface prep solution. Take 10 to 30 minutes depending on merchant strength and temperature. Scrub the etched surface with clear water and a fingernail brush to expose clean but darkened metal. Examine under strong mangification like a 10X jeweler's loupe. Note differences in etched appearance between annealed and hardened sample. The annealed sample will be of uniform appearance. The hardened sample will shade from the center to the surface. This will tell you the "case" thickness attainable with the material represented but that particular sample. Home metallurgy can be made to be quite sophisticated using simple low tech processes.

[@kwader_1404]

man you seem like a connoisseur in this subject. im from tunisia and i make butterfly knives ( i just started and only sold a couple) a customer complained that the edge broke and im looking for a solution to harden it even buy 10 percent im using mild steel (please dont ask why as i can go on a rant for hours on how not industrial my country is and i dont have a forge to blacksmith my own blades ..) long story short can you help me with suggesting whats the best solution for a slightly longer edge witout breaking? (he sent me a picture its actually bent/crushed in the blade)

[@MrLee-cy1pw]

At 4:30 he's talking about the recrystallization temperature. When a metal reaches this temperature the crystalline structures within the metal begins to grow and merge with each other causing the metal to be softer and less brittle.

[@malcolmbuehler5619]

forging with sandals? you are a brave man

[@tb4340]

Missed the previous rebar vid - but relieved to see from the insert I am not the only one forging with flip flops! 😂

[@wayneflint8077]

An Aussie guy done it years ago. If you punch/quench through the TT curve fast enough you can harden steel with less than 0.04 carbon. The product/formula he developed was quenchall.

[@kwader_1404]

can you explain what is quenchall

[@holleyciggy]

the faster you get your metal from the fire to the quench the better

[@1superMADpickle]

a blow drier and a toaster oven... brilliant sir i love this

[@watermain48]

Testing it after the quench with a file might have told you something...

[@baladar1353]

Good vid, although I want to encourage you to forging in slippers. It is very clever and safe, you can be sure that hot sparks and scales won't ever burn your feet.

[@ValMartinIreland]

British Standard EN 1 is for low carbon steel. EN 8 is a basic medium carbon alloy steel with few alloying additives. EN 19 is a medium high alloy steel used for machine shafts etc. EN 24 is a high carbon alloy steel for hard heavy duty parts.

[@chrisgriffith1573]

OK, I'm not a blacksmith, nor am I a welder or have any qualifications a a metal worker, but my humble "common" knowledge of smithing tells me that when you hammered the three pieces of steel, no matter what they where, they now have qualities which promote hardening. So you upgraded the quality of the metal by merely hammering it into shape.

[@tonyduncan9852]

Roast to red heat in an oven while surrounded with carbon. Pack within a steel tube. Six hours will give you a 1/32" skin of carbon steel. The inside will be tough, the outside will be hard. There are proprietary surface-hardening mixtures, but plain carbon, graphite or charcoal, will work.

[@najroe]

If you pack apiece of 2mm wall tube with charcoal powder you get inside carburized, then you weld the two carburized sides together and get steel with "soft" outside and hard inside great for small carving knives and the "soft" steel is less prone to rust as bonus (large part of blade)

[@najroe]

By the way, by weld i mean forgeweld, normalize after weld then treat as O1

[@tonyduncan9852]

That's a perfectly good idea. You need a hard edge, and pure iron hardly rusts at all.

[@najroe]

It has been used for knives here in sweden since vikings roamed, modern laminated Mora knives re more or less a more controled way of doing it.

[@wayneflint8077]

Yep that's how it's done you can turn a nail into W1 on the outside and a good tough core in the center.

[@longchamps23]

Ive seen steel similar to this before. Early(ish) military tank. I believe from an English model. Wanted a knife made from old tank armer that had been deployed in WWII. it was a very peculiar "mild" steel. It had all the properties of a fabrication steel. Yet, hardened better than I could have ever hoped from a hunk of steel that was never meant to hold a fine edge. Its almost like they ran out of plates and threw in whatever they could find including the kitchen sink.

[@shotgunsam23]

For a spark test you want to use a belt grinder or bench grinder. Angle grinder discs do something funky with the sparks.

[@tragikk03]

a bench grinder and angle grinder physically function identically, how would an angle grinder be any different from a hard-wheeled bench grinder? this is internet gear-addict theory and not real life.

[@shotgunsam23]

@@tragikk03 diffrent makeups for the stones vs the discs

[@kaaelo0]

I was expecting something here, but due to the fact I see blacksmithing in flipflops, I am not taking any statements or recommendations seriously. Simple as that!

[@wanderingcalamity360]

Good thing none of us were taking *YOU* seriously, anyway.

[@HiTechDiver]

So if he told you the metal was hot coming out of the fire, you wouldn't take him seriously because he's wearing flip-flops. Admittedly, not the wise thing to, but you only continue in your ignorance and pettiness if you let something like that close your mind to any knowledge that might be gained.

[@kaaelo0]

@@HiTechDiver people watch these videos and they usually take examples and/or recommendations how to make things in videos like this. People directly or indirectly can take some practices of this into their workshops, intentionally or not "wearing flipflops" drop something on they foot and loose fingers for example. Not everyone will do that or whatsoever, but my main point is that if you are of some sort of content creator like this, please advise SAFETY in videos. Do whatever you like and how you like when your alone or so, but do not promote bad safety habbits in workshop. It's not the ignorance I close my mind to, I am not taking serious this type of attitude. No need to jump in and defend anyone here, that was just my opinion, like it or not, I have some point in it.

[@blargkliggle1121]

Just look up clickspring, he's got a video about how the Greeks and Romans case hardened their iron.

[@cnoreen8732]

black smiting in sandals at 2:00 .... one minute later. recommends particulate mask.... you know... cuz ppe is only for your face

[@mergrew0110]

CNoreen. Yeah, I noticed that! Steel toed shoes/boots as a must. A lot of youtubers neglect their feet. Even in a woodshop the possibility of a dropped tool or plank is very real, not to mention the wood shavings and sawdust being an irritant, same must be true of a metalwork shop. Real smiths always dress for protection, as witnessed by the state of their clothes!

[@theshauny]

I was thinking along the same line but with the mis use of the grinder A: no gard and B:cutting the wrong direction, cut with the wheel not against it so if it grabs it pulls it away from you not push’s it into you

[@HWPcville]

I have a friend who dropped her kitchen knife on her bare boot and sustained a severe injury. It cut major important things in her foot and she was laid up for weeks.

[@userer4579]

Those are safety sandals. I agree with theshauny, however, regarding the grinder with no guard. Using a grinder with no guard (like in the video) is one of the leading causes of injury in industrial settings.

[@Mr71paul71]

stick ppe right up your rear end. ppe is for Snowflake's who don't know how to do their jobs correctly

[@davefellhoelter1343]

As a "Tradesman" of Multiple Trades? I learned of an actual QC test named the "JEEP TEST!" believe it "or Not?" an inspector charged with inspecting my exothermic welds used a 2lb hammer and let the hammer fall an arm's length swing almost under almost it's own weight, if my weld survived with little to no signs of impact or damages, I passed. "Supposedly?" this test was named after the Hammers issued in WWII jeeps tool kits and a Seabee's test development for testing welds in the field.

[@saxonforge]

Mild steel does not mean soft steel. Structural steel AKA mild steel is 1020 ( 19-22 points is the tolerance most steel mills rate it at.) and can reach a hardness of about 50 + Rockwell C when quenched in water. Its not a good choice for knives but can become harder than most assume. The term Mild steel was introduced about 1800s and actually meant semi - steel. Re bar, nails and rivets are very soft and are about 1008 which is less than half the carbon content of structural steel. You were more than likely working with mild steel, welding shops don't usually work with tool steels.

[@ThomasRonnberg]

I like how 95% of knifemakers don't pay attention to what engineers have to say about the basics of steel theory. They waste so much time testing ghetto heat treatments when they could just check the graphs. They generally think that bringing any random steel to non magnetic means the steel is fully austenized. Or that normalizing more than once is necessary on a knife profile.

[@ralphyvarzetti5040]

As an Ironworker, i work with all different carbon steels on the daily. The color of the sparks is really how you can get a ballpark rating. From bright yellow to dark red is low carb to high carbon. Heat kills magnets so dont check when its hot

[@pierrefourie74]

It has to be checked when it's hot because when it cools down the magnetism comes back

[@TimKollat]

the dust mask looked perfectly fine. Of course the outside is going to be dirty, the inside was clean. A respirator will do nothing more than a dust mask except for filtering out fumes/chemicals

[@robertdevito5001]

Even that depends on the mask, some of the better ones will filter out a lot of fumes as well.

[@Ironsights85]

lol! talks about safety equipment, forges in flipflops, nice!

[@johnbarbero757]

3:27 The good old days when you could just go out and buy a face mask and TP...

[@chrisjackson9102]

The most common type of steel for structural members (looks like a C channel there) is ASTM A36. Probably what you've got there. It's similar to 1018.

[@michaelstorm8578]

It would be interesting to see how the different pieces would drill.

[@eastlothian98]

Grinder is upside down to me; if it bites the metal, it's gonna bite you next

[@maxmeier4039]

Structural angle iron like that is actually usually a bit higher carbon than mild steel. (1035-40, very Approximately) You want structural steel to be fairly rigid, and not deform. It’s definitely not a real high carbon steel, but you can make a decent knife from it. However with knives, there’s a huge difference between decent and good.

[@danbance5799]

Grade 8 bolts (the yellow chrome finished ones) can be used to make a nice hard knife. They're relatively inexpensive (my local hardware store sells them for $4.39/pound). A 1" x 5" bolt can be stretched into a decent knife. Yes, there is better steel out there, but those bolts are cheap and easy to obtain. Be sure to grind off the threads before you start.

[@robertdevito5001]

That's not a chrome finish, it's zinc... DO NOT BREATH IN THE FUMES! They're fairly dangerous! Also, why cut off the head? It'll stretch just fine, I made a miniature knife out of a 5/16x1 inch bolt, the handle was the threads, the blade was the head, the blade was a little longer and a little beefier than the handle which was just kind of flattened enough to make the threads look like they were part of a knife handle rather than threads from a bolt.

[@ajhproductions2347]

My bet is that was A32 structural steel if that was a piece of channel. Most big plants have their machinists and welders work with that. Oh and try using thinner pieces of steel for bend break tests to check the grain. Just my two cents.

[@williambecking8765]

spark testing isnt really accurate when using an angle grinder . the wheel throws its own sparks with any ferrous metal

[@jojomcgee3430]

Lol! I agree that it's not accurate but....

[@baddoggie101]

In order to throw sparks, it would have to be worn away substantially and produce a high enough temperature to nearly melt the material being ground. The silicon carbide and silicon oxide of the grinding wheels won't be raised to a high enough temperature to do that.

[@williambecking8765]

@@baddoggie101 i posted that two years ago how far down the comments page was this ?

[@Imwright720]

I have a friend that builds industrial equipment. He commonly uses carbon steel but also 304 and 304L stainless. He has other stainless but it’s not always marked. I get scraps and have started making knifes. I can get steel up to an “1 thick. The practice is free except for my time and a little electric. I haven’t been able to make a knife yet that I would want to spend the money on for knife steel. Maybe after I do it for a while I’ll buy a piece.

[@woodmitestovecompany3568]

Never ever ever temper mild steel. You cannot get it hard enough to break. Just quench it. It is impossible to develop a super saturated Martensitic structure that will fail critically easy. Try it quenched and that's it. You can harden it.

[@XAGR-hn3qt]

Wood Mite Stove Company so mild steel is what exactly I’m new to this so I’m trying to find out things from people that sound like they know what they’re saying lol

[@woodmitestovecompany3568]

Black hawk assault Bullet storm any low carbon. Usually 1018 or a36 variety. When you get it red give some time to soak and disolve carbides too don't just get hot and quench.

[@ludwigekner1279]

You can also impact/work harden it. If the blade geometry allows for it, you can use a large ball peen to hammer the edge by disrupting the lattice structure of the steel. If you are not careful, you can introduce cracks in the blade, but the edge gets significantly harder.

[@joandar1]

To all in this thread, Mild Steel, from a scrap bin of a business that does fabrication and such. IS/ WAS it mild steel? Sparks hint towards it not being mild. A good test I would like to have seen is to have the sample/test piece cut in four and that fourth option not heated at all with the same basic tests shown. On another note it is each to their own, I am not thrilled in the way the grinder is used in this, I prefer to have the sparks come to me and the machine if you allow it to grab, go the other way. I am aware it is the choice of all of us as to how we use our tools, I am also aware that people with no experience with tools be they young or older see these videos and may mistakenly think this is the way the Engineers that designed them intended them to be used. I think that would be wrong. John, Australia.

[@dooseyboy]

I picked up a really nice bit of scrap metal recently and my brother reckons it's make a great knife. Now I just need to figure out if it's carbon or not

[@naeemakhtar1980]

I am a blacksmith, could you please tell me which oil you used to harden the mild iron?

[@Bentriverrusher]

I have case hardened mild steel with a cutting torch adjusted with less oxygen then normal so that it has a black smoke flame. Then a cherry red and quench. It only does a 1/2 to 1 1/2 thousands of hardening. But that is good enough for some things.

[@ryanwatson-uv1kh]

Thanks. You expressed some good info.

[@johnwalker5938]

Judging from the spark pattern thrown from your grinder in the intro of your video the steel plate you obtained from the the welder is a carbon steel not mild steel.

[@Migs3]

Excellent video. Thanks for taking the time to film and edit it and of course for positing it for our benefit. Keep up the good work! -Migs

[@dirkventer8112]

Adding hardening powder works dont know what is in there but it does give mild steel a bit more strength do too many cycles and its snaps off with bending it to far.

[@forrestcrabbe]

take the pieces back to the welding shop or a welding class at a tech school (if one is nearby) and have them put it on a bend test machine. make sure you tell them the steel has been hardened so safety measures can be taken.

[@samlogosz8422]

I restored an old hand plane. It needs a new iron. Could I take a piece of mild steel and get it red hot and dunk it in cold water.

[@Dr.Scorpio]

Nice video and great work. Thanks

[@ThomasRonnberg]

you dont necessarily need a lot of carbon for martensizing if the steel is martensitic. then it'll get hard. not sure about the edge retention

[@ddtrahan]

I do Commercial Demolition and come across old steel all the time and always take home. Anything you recommend is the strongest to look for?

[@simsimsimsimon]

Very cool show 😊 watching dit before school 👍 Greetings from germany!

[@erichasu737]

Indeed if you want comparable results, you should buy brand new steel stock from an official vendor. It is sold ready cut pieces, or cut by order. I got a steel plate from scrapyard, which turned out to be high carbon spring steel from a truck leaf spring, although it looked exactly like any scrap metal plate. The stuff sold in hardware stores and steel vendors is uniform in quality, for example S355 cold drawn in Europe. If you think that crap steel is used for construction, you are way off. Strict standards are used to sample every batch, because substandard steel can lead to collapse of structures, which is way worse than having a bad knife blade.

[@borderlessnature]

Just found your channel. I love your videos! Thanks for the great presentation 😎

[@FargoFX]

Tas Hortobagyi thank you!

[@SirSavage01]

You can see from the flower-pattern sparks that the chopper knife steel was not mild-steel but high-carbon.

[@Creator_Nater]

Nice work!

[@smithsmarine4885]

to case harden Mild steel you need to add carbon try enclosing your part in a source of carbon (powdered carbonised leather and salt ) then wrapping it in a clay wrap to make it air tight then heat it bright red /orange for 25 mins then break open the package and then quench in oil then you need to temper the part to a golden colour with a blowtorch careful not to let it go blue or all your hard work will be ruined

[@go7awarsha998]

Lovely job. Thanks. Just expected the tempered piece to act somewhere between the other two pieces, but it didn't!!

[@robertdinicola9225]

Leaf springs, lots of steel bedframes. Ive used old brick layers chisels and saw bldes too.

[@tommoores1531]

When hammering at the vice, hammer into the rear jaw, going the other way puts impact on the screw threads and might break it

[@nathanducharme5697]

Very enjoyable video 🤌

[@aaaaaa-lt2tl]

I engaged my safety squints even watching this

[@thepreserver83]

cheap steel for amateurs to make knifes is the only option to go at scrap yard where you can cars or trucks and take the leaf springs, build the knife from leaf springs is best option.

[@jmaros15]

Do any KZbinrs ever use the guard supplied with their grinder?

[@alpaca6766]

Have you ever broken the front of a vise. You will hammering towards the weaker part of it. Hammering back to the main body is far stronger.

[@canlite]

Haha. My dad use to pull me away from saws like that. 😂 pulling clothes are quite effective. Now a few times if it was at a range he would use a chunk of wood and throw it at me. Lol.

[@_cul8r_]

I liked the video but found the title to be misleading since you didn’t actually demonstrate how to harden mild steel. Should have said something more like how to test unknown steel carbon content or something. Anyway, just a minor observation, like I said, great video and a like from me. Cheers!

[@robertdevito5001]

Yeah, I figured it was gonna be a tutorial on carburizing steel by the title.

[@engrSdk]

Is it possible to make leaf spring from Mild steel Flat bar carbon contains approx. 0.17% by Heat treatment? please reply.

[@samlingo9429]

Are you really running your grinder the wrong way with no guard on it in a tutorial? My buddy cut his entire face in half doing that and he is a 20 year metal guy. I hope no younger people watching this follow that particular example ive seen first had the irreversible damage to not only your flesh but also your confidence. Not ranting btw its just not a good thing to show when teaching

[@theodorekafalias8998]

Those dust masked are designed to collect dust like that. Most have fibers that are statically charged..

[@JonesAndGriesmann]

That's A36 low carbon mild steel, I can see it from here!

[@dzieslaw35]

Great explanation!! But you could better wear jeans or working pants with long legs and leather working shoes in case a red hot metal piece will fall on the ground and that will probably happen when you forge. I got Lucky one day when I was forging a piece felt and it was burning trough my pants but my cowboy boots saved my leg.

[@peta1001]

Did I miss the temperature units (Fahrenheit or Celsius) here? Please, explain.

[@captainchaos3053]

What is the anvil you are using? I am looking for a small anvil that won't break the bank. Any advice?

[@BradsWorkbench]

Have you tested anymore scraps since making this video? How did the edge hold up when u hardened that butcher knife u made from mild steel?

[@operator8014]

Good to see that 3/4 of the comments are from people bitching about how unsafe you're being. 🙄

[@funkybassguy68]

Hi all, i am a complete newbie at this and my question may be stupid but would cold roll steel be better than hot roll steel as far as hardening quality goes?

[@churchmouse2540]

So quenching in water hardens steel? I'm brazing sheet steel. I'd like a strong joint

[@londiniumarmoury7037]

There's a few ways to harden mild steel, Super quenching, Work hardening, and Case Hardening.

[@kennethkustren9381]

Guaged Sheet metal, Channel, and Beam all have different properties. Their plausible physical capabilities are commensurate with their uses. A car frame is not the same material as the body, or engine block, soooo .... ..... try a scrap engines camshaft. Valves probably will be a nice section for smaller items.

[@RDALEHOUSTON]

thanks for the video,, but you did not say how to harden steel,, or can you harden this kind of steel so can you do a video an use cold an hot rolled steel the piece you used not should what it was,,ok now i want to make some dies for my bead roller ,,.can i use rolled steel these will not be used everyday, so tell me what you think if i try them,they will work, might work,, don't want to give your thought ,or wasting my time ,i will need 70set or more,,remember ,, why try,, got to cut140 cuts or more,, bore,, lathe & milling,,i know buy an make a set of 2 i kno this ,,i may do ,,but i'm asking you what you think,,,thanks great video site,, bye from NORTH CAROLINA

[@theodorekafalias8998]

Bro... All you need is some "Cherry Red" case hardening powder.. I've made drill guides to actual fixturing bosses/ standoffs etc with basic mild steel.. and hover around 400 brinell hardness.

[@theodorekafalias8998]

I always do a oil quench after the cherry reds been done twice. Works on blades and you won't have a problem shattering

[@dangli9]

How about some protective footwear. I was worried about your feet all video. So much knowledge required for making blades. Thanks Dan

[@Heywood-----Jablomeh]

I am an Ironworker who comes across lots and lots of scrap pieces of what we call A36 mild steel and sooo soo much of it just goes in the job site dumpster....good to know it could be hardened or tempered or both to become fairly decent practice blade steel! I've been watching for a while and wanting to try my hand at making blades....with that said being said I could throw a few pieces in a box if you like just pay the postage!

[@killerlobstermoth]

I like how your son was entranced by the fire and you pulled him away by his shirt. That made me laugh.

[@KnowName33]

I had a piece of thick 2 inch by 2 inch bar stock very soft Steel at work that I cut to the shape of a sheet metal hammer and I'm talking this is some of the softest steel I've ever messed with either way I had an Ice Bucket that was 50% water 50% ice cubes and I heated with an oxygen settling torch 3 x 2 * cherry red and then the last time I got it all the way up to a nice gold and orange before quenching that was seven years ago and it's one of my best hammers

[@kwader_1404]

did you temper it after quenching ?

[@KnowName33]

@@kwader_1404 quenching is part of the tempering process

[@kwader_1404]

@@KnowName33 I meant normalizing it. I'm having the same issue brother do you think a butane torch can do the same job?

[@baddoggie101]

Would auto leaf springs be a good source of high carbon steel?

[@kwader_1404]

sure

[@christheother9088]

I was cooking bacon once and I was only wearing socks on my feet. A little blob of grease flew out and hit the sock. Amazing pain. Took 5 weeks to heal. Thats all I could think about seeing those sandals.

[@Lancair70]

The socks held the superheated grease and made the burn way worse. Ive had major burns from hot coffee when wearing socks, bare feet is better than socks. Having said that, bare feet when working with metal is a BAD idea any day!

[@MidGCobra]

Wicked vid for a newbie bro..

[@laynesimons808]

Coal forges can carburize steel!

[@tonyduncan9852]

They can also sulfurise it. That's not nice.

[@mv2442]

nope,not that easy

[@FT4Freedom]

Coal forges don't carburize steel. Carburization requires anoxic environment. Carburization requires a container to contain the carburetion process.

[@edwardlance2379]

@@FT4Freedom Exactly, and even then, the carbon penetration is very little. In fact, it is used in milder steels in order to case harden them since there is no way to infuse carbon throughout the entire piece. There are several good videos here on YT discussing carburizing and case hardening.

[@dennisa6132]

@@edwardlance2379 Clickspring did tests on this and shows how to carburize, it went entirely through one piece, granted not very thick piece but all of them where a lot deeper penetration than I would have though, made fully functional files from the lot. I don't think you need more than a fraction of an inch of penetration to make a durable drift

[@damirdze]

Protect full face from the tiny particles also , they cause the tiny cracks in the skin and premature aging.

[@richb2229]

Structural steel like that piece of channel is typically A36 steel which is low carbon (0.26%). It’s difficult to say exactly what you have there....

[@arthyzlive3987]

Can i do this to my non hardened steel baton tubes to make them hardened?

[@docgalt2801]

Good information