knifemaking

How do you know when a piece of steel you found as scrap needs to be hardened, tempered, and annealed?

I am no expert, but I know a few things and I am sure folks will correct me if I am wrong. First annealing is a process where you soften the steel so you can work with it.

Makers have told me if to take a file and run it across the steel, edge wherever and it slides across without taking any steel it is already hardened that is how I know how to check.

you can do a sparktest.....trya piece of plain iron...then a piece of steel you know is good steel like a file or some bought steel...then try it on the piece you found....does it look more like the one or other...then you can heat the tip or cut a small pice of ..then heat to none magnetic and quenc in oil.....put it in a vice and break it if possible..if it snaps you have a steel worth making a knife from.

when heattreating the finished blad, heat to none magnetic and quench in hot oil.......then you need to feel your way on the annealing...start with low temp and work your way up untill you have the decired hardness.

The best advice is to "buy" a known steel. Even if the steel you found is suitable for a knife, you will not know the chemical composition, and thus will not know the proper temperatures for annealing, hardening or tempering.

Also, you will here things like:
- Automobile leaf springs are 5160: The truth - Not always
- Large circular sawblades are L6: The truth - Not always
- Planer blades are D2: The truth - Not always
- Files are W2 or 1095: The truth - Not always
The list goes on and on.

If you know what you are looking for, the spark test can help determine whether a piece of steel is high carbon, but otherwise you're out of luck. Even if you have a good eye, know what to look for, and determine that the piece of steel is high carbon, you still don't know what type of steel you are dealing with. Is it a spring steel, a tool steel, a high speed steel, etc., etc.?

I'm not trying to be a wiseguy here. I'm saying this with caring respect. I am assuming that you are just starting out. A new maker has enough problems to deal with, and just doesn't need the added burden of working with a "mystery" steel.

Oh yes...listen to Primos....! I made knives for years from files, sawblades and springs....When I discovered 01 I wished I has never used anything else...made alot of knive sin 01 before changing to stainresistant steels like ATS-34 and RWL-34.

You will get temted by the fact that the materials are free or close. Well.....you will probably work 3 times as long on recycled material than new steel and the endresult might be worth lltle more than nothing if it is bad steel or the heattreat did not work ok because of the unknown factors...then you have spent time, grindingbelts and handlematerials on something that could have been excellent steel....

Primrose and Anso are so right, I made knives for years out of auto springs, I finley got tired of throwing away blades I had spent a lot of time on because of a crack or other defect.
Now don't get me wrong there are a lot of knife makers out there who use car springs with very, very good results. These makers also know what thay are looking for, thay have a lot experence and do fine work. Gib

Unfortunately, the dark side is always calling....

I was messing around back in Feb with a leaf spring I've had for quite a while. I was making about a 26" bladed Saxon sword. I had spent several hours of shaping and was finishing up the tip. I pulled it out of the forge and noticed an odd non-uniformity in the orangeness. Sure enough, there were a bunch of little cracks in one area and the last 4" just kinda fell off after it cooled! I wish I could say I was brand new and didn't know any better, but I had several feet of a wide variety of new steels to choose from...the spring just seemed like a good idea at the time!

Plain carbon steels are inexpensive and easy to work. New 5160 is pretty cheap as well. Scrap yard steels are good for making mace heads, war hammers blacksmithing forms and stuff such as that, but too unpredictable for knives.