Heat Treating, general discussion

First, I don't give advice, I only relate what I've observed to work well (disclaimer). The shops I've seen that have the best results i.e. hold up well and don't break do the following: Take a VERY short heat, cut the junk off the end (even to the point of beating some cold steel at the back end) and forge out the point, nip off the end, grind and quench in #2 heat treating oil. Simple, right? Why does that work so well? By far the worst sin in sharpening is taking too long of a heat and screwing up the temper farther up the shank. The second is forging it and laying it aside to HT later. This causes the same problem, the heat in the point migrates up the shank and rui…

I'm going to resharpen a couple jackhammer / breaker bits for a friend. As a favor, no pay, no guarantees, standard disclaimers, etc., etc. First, would you harden in oil, brine, or water? Second, what color would you draw the edge to? Thanks in advance, Don

Another question from me. You guys are really helping me out thank you so.. I am having a problem after I forge something and quench/cool it in the water, it gets rust or what looks like rust on it. I like the unfinished look but the rust color doesnt look good. I am having to wire wheel all the color off just tomake it presentable. Could this be from not wire brushing good enough before quenching? Any help?

The following link to Houghton Intl. takes you to a page that has .pdf file discussion of what happens when you quench in various mediums. Houghton Click on heat treating in the left hand column. The discussion includes cooling curves for different kinds of oil, water, brine, etc. They are of course selling their proprietary and safer, (radically more expensive at our level of use) quench liquids but the info is a good illustration of what some of the guru's have been telling us about what happens when we quench.

I think this may be the best place to post this. If not please put it in the correct area. There is a discussion going on at a firearms forum I visit about what caused a crack in a 1942 German WWII rifle. There has been some debate about it being a stress crack from the heat treating, a crack cause by too much pressure from an overloaded cartridge causing the bolt to be set back and putting undue stress on the receiver bridge, from the receiver hitting something/being twisted or a combination of the above. I was wondering if any of you could shed some light on this interesting little puzzle. The thread is located here. If you can not see the pics without signing up I …

I am interested in making my own clay mixture to try differential quenching. What are some different types of clay one can make? Which one is best for knives, swords, etc.? Which one is easiest to acquire/make? I know the basics behind the differential quenching process, but almost no idea about how to go about acquiring or making the clay application itself.

Over the last few months that I've been a member here (and blacksmithing), I've read several references to metal hardness that are, quite frankly confusing to me. Specifically, in referring to the use of springs or files for knife making, flint strikers or tools What's confusing to me is this... While these are good very hard metals, once you've brought the metal up to a very bright heat, doesn't this hardness go away until a proper quench/heat treat happens? Or is there something I'm missing in the metalurgy class I forgot to go to? Thanks, David

In the Foxfire book #5 there is a chapter on gun smithing flintlocks. The frontier gunsmiths years ago made their own springs for the locks they forged and(apparently unheated) quenched the springs in boiling lead. They were then dipped in linseed oil to "temper". Later, the springs were reheated to draw out the hardness. Does this process make sense or do you think the author of the chapter misunderstood? I think Wallace Gussler in the old video "Gunsmith of Williamsburg" demonstrates this but I cannot locate my video? Is this a process worth trying or is the burning oil technique reliable for springs? Thanks, Bob

When quenching mild stell in super quench, assume I quech when it is a cherry red - much hotter and I won't gain the benifit of using super quench. Am I correct? Thanks!

I'm relatively new at balcksmithing. A local blacksmith explained that when the steel heats to the point that it's no longer attracted to a magnet then about the right temperature to quench. He said this is easier and more accurate than judging temperature by color because it works the same under any light conditions. The quenchant would be water. A couple of questions, Will it work at all, Will this work well with 1040 steel, in small sections up to about 1.5 inches square. He also recomended plunging the end of the tool being hardened about two inches into the quenchant and then moving it up and down a little until it cools completerly. Later he would d…

I was wondering if anyone can tell me if spring steel retains its springability if heated and worked on the forge. I have an old rifle which needs a hammer spring. And getting parts to Canada is very difficult. I have springs in the shop will they be of any use if I form them to what I need ?

I had a chance to play today and took a Truper brand 3# cross peen hammer and made a diagonal peen hammer out of it. It was not as easy as I thought it would be. Clamping the peen in a vise and twisting just did not work. I left it in the propane forge to cool after working it so it would be nice and soft for final filing and shaping. Now, after it cooling over several hours, will I need (or want) to normalize it or do any additional thermal cycles before trying to harden? For hardening, a piece of metal this size, what volume of oil should I be using as a minimum? Will 3 quarts in a 1 gallon paint can be adequate? I figure if I find it too soft (file test) af…

Hello, I have a problem I hope you experts can help me with. I have had 250mm diameter disks cut from 6mm mild steel plate. Some of them are warped, and I have heard that heating the plate can 'destress' it and cause it to pull flat. Is that true? And if so, to what temperature does it need to get to? Could I do it by heating over a gas ring?

Hi, I have acquired a 4" round bar (piece used as one of 4 legs for a huge stamping machine) that I want to heat treat one end of before setting it upright as my first anvil. I thought that I could build an "in the dirt forge", use charcoal (no coal here) and set the bar (that will be 26" long so it will weigh about 95#) on a set of home made rollers on the ground .... that puts the bar horizontal to the dirt forge and will be at fire height ... with the rollers I can turn the bar like it's a pig roasting and have the end, about 4-6", get heated evenly. Once at the right color I can then roll the bar to a place nearby with vermiculite in a hole and cover the end up st…

I have a shaft from an auto transmission which I forged into a raising hammer and was wondering what colour to draw it to? (4140 steel) Thanks!

Dose anybody know if you can heat steel to a yellow heat then dip into beeswax for a non rust effect,keep a slight shine. Thanks very much in Advance

While at the local steel supply I noticed that they had some steel they called stressproof, on the sheet it was called 1177. I can't find a whole lot of information on it. It is supposed to be hardenable and good for tools, cutlery etc. Anyone ever use it?? I picked up a chuck of 1/2" to try working with.

I am thinking about fabricating a large pry bar for moving heavy equipment. (I'm too cheap to buy one for $140). I have the tube steel for the handle and some 1/2", approx 3" X 7", plate to make the working end of the pry bar. I plan to cut the fork shaped plate, bevel the end, heat it up, 2" from the end, to bend it at an angle, and before I weld it onto the handle I need to temper or heat treat the plate. I don't have a forge so I plan on using a rosebud torch. I guess I need to heat it up to red hot & quench it in old motor oil? Then put it in the oven & heat it up to 400deg to temper the plate? I value any help and imput. Thanks, Les

:confused: Glen when you move a thread please post on the moved it to where it went -- like my ? on saw mill steel blades I haven't found where you folks put it yet thanks Steve

what is the correct psi that I should use for a cherry red glow and not hotter than that , if that is correct color.

Good day, Being a a starter at this questios of blacksmithing and not having a lot of money i've managed to get in hand of two pieces of RR track with 1.2m heach. I'm now proceeding to cut one of the pieces in half to make an anvil but i'm finding it very dificult to cut due to it's hardness. I'd like to know if I can anneal it and once made to retemper it and how to do this process. Thank you for all your help. Guerreiro

1045 fully hardened to about 55hrc ( http://www.matsci.ucdavis.edu/MatSciLT/Other/Files/HT-Steel.pdf ). Would it be too brittle for a hardie, chisel, punch to use as is without tempering?

I'm sure this question has been asked a thousand times, but if you have any info i would appreciate it. How is h13 to forge? Do you stick to a specific temperature range? How do you make your chisels, punches, drifts etc? Do you mostly grind away excess material or do you forge to your wanted shape and then grind edges? I ordered some 3/4 h13 to make tools, and i don't want to ruin good tool steel as i am new to this whole process. I wanted to start out with some durable stuff for my first tools, but from what i have read, most people talk about spring steel, not h13. I understand it is quite durable, but cooling while using for hot work is important. I have heard…

I'm confused: How do I learn what non-magnetic looks like when every magnet I try burns, melts or disintegrates when I attempt touching it to the heated steel? Yes, this is in open air, and I am allowing less than 1 second of contact time. I have tried an extension stick magnet from the auto parts store, I have tried several refrigerator magnets too (some got gooey and melted) When you were learning about temperature, how did you avoid burning up your magnets? Did you use another method of testing temperature? I just had a "duh!" moment. How about I stick a magnet to one side of a steel bar and see if it induces a magnetic field in the other side. …

I got 2 garage door springs cut rings off put in fire made points on ends curled them then made it into the C shape heated the striking edge HOT red diped in water just the striker edge. Looked GREAT tapped it after cooling with a small ball pen because the curls were not even and it broke in pieces. Can someone tell me what I did wrong and why??