So, you want to forge knives… Well, I just started myself, only made a few blades so far. I have learned some information useful to beginners that might not be readily available online, or scattered all over the place. These lessons learned might save you some time, aggravation, even a few dollars.. Follow any advise here at your own risk, I am no expert and forging is inherently dangerous.
About forging: Forging is not just that, hammering a red-hot piece of steel into a blade. You need to consider what else comes into building a knife. A lot of time will be spent grinding, sharpening, and polishing. If using sand paper gives you unpleasant goosebumps, or you cringe at the thought of getting burned or cut, you might want to look into knitting. Heat treating is not as simple as plunging your steel in water. Some knowledge of metallurgy about different steels and what happens to them at different temperatures is a must. Annealing, normalizing, hardening and tempering are important phases in creating a blade. Then you need to make a handle, sheath, and sometimes apply different finishes. Building a knife is a whole process, forging is only part of it.
Forge: I started by building a charcoal forge. It worked, but it is slow and dirty, a pain in the ass, really. Sure, It only cost me $60, and I could have built a better one. Gas however is fast and clean. I bought a $200 forge on Ebay and never looked back. The next one will have a round shape though, and be covered with refractory cement instead of KAOWool. A round forge body creates vortexes resulting in a more even temperature and probably gas saving. With a hard refractory coating, you will never breathe dangerous ceramic fibers.. Coal is another good option, also dirty, but better in my opinion than charcoal. See my gas forge here.
Steels: Many beginners will try to find some scrap steel at the junkyard. You might get lucky finding what you want, but you might not. Spending hours hammering steel to find out that it won’t harden is no fun. I just ordered six 3/16 x 1” x 60” bars of 1080 from Admiral Steel for about $90 (with shipping)! That is enough to make from 30 to 40 large knives. Less than $3 per knife. Mystery steel is like mystery meat, you really don’t know what’s in it and most of the time, it doesn’t turn out to be that good. 1075-1080 is probably the best steel to start with. It is a simple steel, easy to heat treat and forge. You can temper it in a kitchen oven at 450F. Tool steels and other higher carbon steels require better temperature control and higher tempering temperatures, around 550-600F. It isn’t worth my time fishing for scrap in a junkyard. I would probably often have to discard half-finished blades, so the savings are really not significant enough. Buy good steel, pick one kind, learn it well, you’ll get consistent results allowing you to refine your process. More on steel selection.
Heat Treatment Anneal every time you stop working for the day. Normalize three times before hardening. Use a magnet to determine when the steel has turned to austenite and is non-magnetic. Go slightly higher, and let the blade soak for ten minutes at that temperature. If you forge or heat-treat too hot, your steel will decarbonize. Quench in warm oil (140 to 160F). Cold oil will actually not cool your blade as fast. Avoid motor oil, it’s too thick. Thin oil, such as ATF or thin mineral oil is better. Don’t move the blade sideways while it cools, but front and back. If you want to create a hamon by differential clay hardening, cover the back of the blade with a refractory like Satanite (1/8” thick layer). Temper immediately after hardening, three times one hour at 450F. If you use a different steel than 1060-1075-1080, find out what the numbers are, don’t just guess..
Anvil: I bought a cast iron anvil at Harbor Freight. It is way too soft! Here is when a trip to the junkyard might save you money. A 100Lbs hardened steel anvil will cost you $400 to $600. Find any piece of steel with a flat surface, as heavy as you can carry. Secure it to a solid base, so that you can forge standing up. Thanks to my friend Phil and his father at Seaboard Steel, I was able get a heavy piece of steel which originally was a jaw that grabs giant steel plates. It must be heat-treated because it is very hard. We welded it to an I-beam and a half-inch steel base.
Hammer and tongs: Almost any hammer will do (you might want to put a nice smooth finish on it’s face), but you need tongs to grab your blades. I started with a pair of wise-grips, but they are too short and awkward to use. Having a piece of red-hot steel fly out when you hit it is pretty scary. Don’t ask me how I know.. (well, I still have one scar on my ankle..) Start by forging tongues. It is easier than forging a blade, and you will need them anyway.
Not the best looking ones, but they work just fine..
Safety: Wear heavy leather gloves and clear eye protection (clear to see steel color). I have a welding jacket with leather sleeves that’s perfect for forging. Make sure nothing close to the forge can catch on fire. That includes your propane hose in particular! Wear a respirator when grinding or changing your ceramic fiber forge insulation. Don’t forget, you’re building knives, they can get really sharp! Blades can fly off your hands while grinding, specially when using buffing wheels. You must be conscious of safety all the time. You don’t want to end-up in the hospital or dead because of a hobby!
Information: It is easier to start with some help. Browse the following forums online:
Document you progress. You might discover that a blade you forged displays great characteristics after some use, and not remember how you made it..
I highly recommend Wayne Godard’s $50 Knife Shop book:
Wayne Goddard’s $50 Knife Shop, Revised
I will add to this article once in a while as I discover new tips or pitfalls to avoid. Anyone with more experience than myself, that’s almost anybody able to forge a decent knife at this time, please add any advise for beginners you may have in the comments section below. Many thanks to the members of bladeforums.com for their feedback on this article!