Heat Treating, general discussion

I am looking into making my own lathe and mill. It would be made from plate steel that I can weld into shape. Once welding is finished it needs to be stress relieved which can be done by heating it to a dull red which is apparently somewhere around 650 degree's Celsius. Now I'm thinking that this might be possible to do in the backyard instead of paying hundreds of dollars sending it to a proper heat treating mob. It might still cost the same amount to set up, but at least then I will have the equipment to make a smaller forge, right. Two main issues I can think of are. 1. The size of it and keeping the heat evenly spread across the part. 2. Keeping the tem…

I've been making some different things lately that i don't want to leave raw or cover in paint so I have been heating different colors in. I have been using a propane torch with mixed reviews. I have an OA torch with only a cutting tip and that was a fail. I only covered it in soot. What am I doing wrong? My first guess is that I need a rosebud tip. Is it worth burning the torch or should I stick with the propane and stop fighting the learning curve? Any other tips would be helpful. I have seen other guys get some great colors up that are very bright mine are there but dont stand out like I would like. Would it help to polish it up first? Most of the art is with …

I found a free download of a heat treating book. http://www.secowarwick.com/htdb/htdb.htm I started perusing it, and it looked helpful, so I thought I would share the link. Phil

Hey all, I have been on the site for a little while now and have read a few of the metallurgy books recommended on this site. I have tried to piece the heat treatment process together but I'm still having some trouble understanding. , As far as I am aware, normalizing and annealing reduce stresses caused by forging, additional heat treatments, etc. The differences between them seem to be annealing is done through heating to either at or slightly above critical temperature and then placing the metal in a temp-controlled substance, such as vermiculite, to slow the cooling process. Normalizing is essentially the same thing except the metal is brought to a temperature …

Would some of you with more technical knowledge share with the rest of us the differences in "Super Quench", Water and Oil as quenching mediums? What is best for what? Is there a quenching medium that is sufficient for "general" work ... or do we really benefit from specialty formulas? Gotta favorite recipe? Thanks ahead of time for your input.

I need to harden and temper a round punch, but I don't remember exactly what my instructor told me to do (I was exhausted and was trying to remember other stuff when he told me). I think it was like: 1. Heat in forge, tip in first, until non-magnetic 2. Quench the bottom half in oil (the side with the tip, not the handle) 3. Put in oven at broil until a certain color 4. ??? don't remember the rest Anyone got instructions on how to best do this? They're made of tool steel but the exact type I do not know.

Hi folks. Looking for some advise , I made a spanner wrench out of a piece of 5/8" sqare stock, hot rolled I think, I don't remember might have been cold rolled but any way I figured before I use it very much I should case harden the end. I probably should just order a can of Kasenit. however I was wondering if any of you blacksmiths out there use hooves for case hardening and if so how it is done? Thanks in advance oscer.

Has anybody tried using a toaster oven using the convection setting for heat treating punches and chisels for use around the shop ? The cook wants a new one and it seems a shame to throw the old one out. One possible part of this plan might be wrapping the tools in foil for treatment to reduce the influence of radiant heat in the process, and use a low tempeature thermostatic probe to track temperature.

I'm in the military and we have to adapt some sheilds to allow for barrels to fit through them. This steel is HHS; is anyone familiar w/this type of steel ? is it air hardening? Thanks in advance.

I'm sure this has been asked and answered before but I can't find it on Iforge nor do the hammer makers tell you. I made some more dies from Ag bar which heat treats similar to 4140 but more wear resistant which is why they're used as rippers and subsoilers. 2.25" X 2.25" is $6/inch which is in my budget...But this time I machined them too deep and cut through the HT layer. So what Rc are most dies treated to? Thanks, Keith

http://aimkiln.com/aimcrucible1411c.htm So I just acquired one of these (scroll to model 1715C without the crucible). How will this work as a heat treating oven? It has a digital control with a couple of ramps. It is alleged to work. Didn't test it, but the new elements are around $40. At this point my HT has been very unscientific using scrap yard springs for making my tooling, heating in my NC tool propane forge and quenching in water or veg oil, mostly hardies and power hammer texturing tooling. I have started making some blades, but have yet to heat treat any yet. After most of a year blacksmithing, i'm just learning how much there is I don't even have a clu…

I see a lot of people refer to soaking. Is this better in all cases, such a high carbon steel with no other elements in it, or more for the more complex steels? I am thinking of making an oven for soaking and wondering if I would use it for all types of tempering. I can see the advantage of controlled temp. In the more traditional way where you heat to color how effective is that vs. soaking, 90% as good on just carbon steel? thanks for any insight on this.

Might should have posted this in the HT section, but I didn't. Trinculo hooked me up with some nice unhardened 4140 dies for my Bull, and I'm looking for some advice on quenching. I've got a vertical blown gas forge that I can take the lid off of, and fit just the working portion of the dies into the forge, so getting them up to temp shouldn't be that hard. I'm going to heat them in sessions to try and even out the heat as much as possible, but I'm uncertain about quenching these. I've got 5 gal of really fast quench oil, Park HB #50, and I've also got plenty of canola. Will 5 gal of either of these be sufficient? The weight calculator tells me the actual weight o…

I picked up a tempering oven, it has a barbara coleman 560 controller on it. I am wading through the pfd on it. I am not seeing a soaking option on it, does anyone have one or have worked on one, that could help me out. thanks.

I am heat treating some h13 hammer dies for a local blacksmith as part of a trade. The dies are about 20lbs each and are for a 120 ln bulll hammer. My question is do I need to foil wrap these in order to prevent decarb or will they be fine without it? Thanks John

Found a well written introductory level FAQ on metallurgy that I thought I would link to. http://home.sprynet.com/~monel/metallurgy_faq_v11.htm Phil

For a while now I am trying to harden 4140 for use under the power hammer. I use 3/4 x 3 x 8 blanks that I bought for a blacksmith magician. I forge them to shape, soak them in my propane forge (with a little excess propane to not produce scale) for an hour, quench and then temper. For quenching I tried old motor oil first and for tempering my wife's kitchen range (400 F). The resulting tool did not hold an edge for butchering one tenon and the end mushroomed. I later heard that motor oil is no good and changed to 3 gallons of canola oil: Same result. Then I added 1 third Diesel fuel to my canola oil to reduce viscosity: still not hard. Finally I thought, even if it crack…

I've been wondering lately: how do blacksmiths make springs? Obviously the steel has to have the correct carbon content, but what is the procedure for "convincing" a piece of steel to spring back to it's original position?

I've searched this site and others on the internet for some tempering charts for the most common used steels and so far I've found one for O1 and one for 5160. Now my problem is that there's several tables for a given steel our there, so which is correct? Can someone tell me if these tables are correct? -Anders blacksmithing.txt

In the months that i've been actively smithing, ive come acros a rumor that i would like to resolve. A few people that i know have told me that when you burn coke hot enough, it will add carbon content to a piece of steel. Is there any truth to this? or is it just a rumor?

I just scored some 2 1/4" round 4150 for a awomse price..Anyway Im looking for the as quenched hardness and any other tips you may have for 4150..Ive worked with a lot of 4140, Im thinking not much different just higher hardness..Please correct me if Im wrong..Thanks

Hi All. I have 2 projects that I am up to that I should have done more research on before starting. At least they are modest ones. 1- I am making a war ax out of an old ball peen hammer. I have aspirations of drawing the blade to bearded ax dimensions, but it is not working as well as intended. When it comes time to heat treat, I was intending to use quenchtex A and temper to a purple 3 times each (yeah, I hang out with blade people). Is it better to just forge heat and harden the edge (1 inch) and let it temper with retained heat? Suggestions? (I also have an old tub o peanut oil and of course water). 2- I am making a double diagonal peen hammer 45 degree to the ri…

I found a crowbar with my lawn mower, and it bent one of the nail puller part, so I have to heat it bend it back and harden and temper it. Is possible with a simple setup. I can't heat the whole thing up, its a 40" long one, am I going to put a hard breaking point on the bar if I only heat and temper one end that I can fit in the gas forge? I don't think that I can just hammer it back, with out breaking the prong, I would guess it work hardened when it bent. Or should I just call it a loss and buy a new one? thanks for the help.

Anyone ever heard of Flash Bainite? http://www.bainitesteel.com/

Before you say this should go in the tools section, my question is about heat treating it. I figured I'd buy some tool steel, forge it to a point and use it as a hardy tool to punch holes. My question is, is there any specific way I should go about heat treating it after I shape it? Aside from the usual heating it up until it loses its magnetism, dunking it in cold water, and then tempering it?