A lot of people use an electric furnace both for both hardening and tempering since you can very precisely control the temperature, and thanks to electronics set a specific heating profile. They were fairly damned spendy(back then and now) and I didn't do this enough to make that affordable. So I used coal, prepped the fire carefully, and heated the quench oil so it would flow well and give the most even quench(and that is one trick I wish I'd learned a lot earlier).
Favorite steels I used... depended on the piece. Big chopping blades, and swords, 5160 spring steel. Smaller blades I wanted to hold an edge really well, generally O1. Once I'd had a chance to try some, I liked harrow teeth; a blade forged of those held an edge really well. Especially when I accidentally found out something: I did the tempering in the oven, and usually did three heats, letting it cool completely between the first two. One night I forgot a harrow tooth blade on its third heat in the oven over night. Lord, that thing held an edge! I did that as part of the process from then on.
Added:
I forgot one: 52100B, a high-grade bearing steel, used in both bearings and the races the ran in. I will tell you, forging a large bearing out to a bar would wear you out; just remembering it makes me wish I'd had or had access to a power hammer. But handled right, made damn good blades.
Things other than knives, anything that would work. I made a LOT of flint & steel strikers and screwdrivers, things like that, from overhead garage door spring, and I could often find a section of a broken one and get it free. Unwinding it was a pain, but worth it. Mild steel for candleholders, eating sets, fireplace/campfire tools, belt buckles, and other things.
I also discovered stone drills, the old kind. Which I cannot find a picture of. Generally either round or, all the ones I found, hexagonal in shape and anywhere from a foot to several feet long for some big ones, with four flutes and a point formed at a shallow angle. You held them in place on the stone and hammered to drive them in. I've found them anywhere from about 3/16" thick to 1/2". You could forge them to shape and then grind to final size, use an oil quench to harden and the go by color(with some experimentation) for hardening, and they made damn good chisels and punches.
Yes, the wondering about tempering on Forged in Fire reminded me of some things. I miss it, though it may be partly why some of my joints are so worn.
6 comments:
I worked in a shop that made all of those alloys, plus about 100 more. Of all the alloys that I ever made, one of the ones that worked the best for getting and holding a sharp edge was 410. We often made knives for use in the shop to cut cardboard, plastic, banding, etc. And we would use scrap 410 alloy that had come back from customers to make them, using just our floor grinders.
The only problem was that often the scrap came in and had been rejected parts for machines that performed some cutting function, and so was sometimes already sharpened. You had to be careful, or it would cut you. I saw more than once a guy cut himself and had to go and get a bad cut on his hand or finger sewn up due to cutting through his glove and then himself.
Of course, the 400 series also included 416 w/sulfur, which was very often used in gun barrels. Not much different than 410, other than a bit more carbon and the addition of sulfur, to make it easier to machine. I am guessing that the alloys like 400 or 17-4 would be much too hard to sharpen, but once sharp, they would stay that way for a long time.
You just reminded me of another one I need to add in, 52100B as I recall, bearing steel
A guy I used to know would make some of the best fillet knives I've ever used out of old crosscut saws. Somehow my ex ended up with all those knives. I miss those blades, the ex not so much.
I hate when the guys want to use temper bead vs pwht; so many things can go wrong and the welding parameters are really tight. We only have one welder i trust to do it.
On a similar note we have a weld between two disimilar steels we do occassionally; its 4130 to a high tensile pipe with a CE of .62 preheat, post heat and soak time as well as interpass temps are so tight that only 1 of 5 welders passes the qualification test.
Exile1981
I don't know if you'd find watching the guy interesting, but if you search for CEE (cutting edge engineering) on youtube, he runs a one man machine shop in Australia and posts weekly videos of his work. If you're looking for humour, watch the out-takes at the end of his videos.
Hadn't heard of him. Get some time, I'll take a look
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