Forging a Knife From a Nicholson File, Part One




About: i love blacksmithing, am a christian, and enjoy viking culture and weaponry. my favorite musical genre is metal, i play a four-string bass, and my favorite band is Amon Amarth. my favorite cars are early 70s...

This is the process by which i forged a knife from an old Nicholson file. enjoy.

From this point forward you are forewarned; forging is a dangerous activity. it includes high temperatures, heavy hammers, and lots of smoke. always work in a well ventilated area, use good leather gloves, and wear eye protection. above all use your common sense, and you will be ok...probably.

Step 1: Coal, or Lack Thereof

maintaining a coal fire can be a challenge. unfortunately, i have no coal. so i use hardwoods and lots of forced air to attain the heat i need. it uses a lot of fuel, but it works.

select your steel now; preferably high-carbon (old files, car springs, (leaf or coil) lawnmower blades,old machete blades, etc. and put it in your coal bed.

Step 2: Forging Heat

Apply your forced air. i use a 3000 RPM squirrel-cage blower with a three inch outlet. as you can see my docile coalbed has become a roaring jet of fire. this setup has the capability to heat steel into the oarnge-to-yellow range. add fuel as necessary while you heat your steel.

Step 3: Bevels

use a pair of tongs to pull your steel out of the fire, and rush it to your anvil (mine is set at a 90 degree angle to my forge, so i only have to turn my body to get there, very ergonomical.) strike the red-hot steel on the edges, flattening it at an angle and drawing it thinnest at the edge. it is very important to use a good-quality, flat-faced hammer for this job. i have three hammers i use for forging; a three-pound flattening hammer to straighten steel with, a four pound semi-flat for general forging, and a beautiful Vaughan 24-oz. ball-peen hammer. i chose the ball-peen for this particular task because it has the highest weight-to-surface area ratio of all my hammers, allowing me to move the steel more efficiently with each swing, and also its longer handle gives excellent leverage.

Step 4: Tip to Tang, Always.

start at the tip of the blade-blank and work your way down, re-heating the steel as needed. be careful to keep your edge straight and true while you forge to prevent annoying flaws later.

Step 5: Final Shape?

here is the blade's final shape (almost) you can clearly see the distinct curve, caused by pulling the edge thin on one side.

Step 6: Cut That Pesky Nub

time to remove the extra nub of steel, what once was this files tang. trhere are many ways you could do this; cut it off with a hacksaw, cut it with an angle grinder,etc. I, however, chose a more traditional route. the hot-cut.

Step one- heat the tang to an orange color.

Step two- use either a cold chisel set in a bench vice, an old hatchet-head, (see picture above) etc. (if you are lucky enough to own a professional anvil you could use the cutting bit with your hardie-hole) and pound the steel over it with a large hammer (i used a four-pounder) or you can set the steel on your anvil, hold the chisel in hand and pound on it with the hammer.

Step 7: Heat Treating

one more heating. this is the heat-treating cycle, where the steel becomes hard and durable.

first, bring it up to critical temperature (oarnge-yellow is just fine) for a half-hour. let it air cool to normalize the steel, very important to make the blade strong and durable.

after it has cooled to room temp, throw it back in. this time heat it to critical temp, and maintain that heat for an hour. immediately  after pulling it out, dump it into a tank of room temp motor oil, not water. this sets the steel in a hard, edge-retaining state.

Step 8: Finished, for Now

This concludes part one, and as you can see the blade is fully forged and ready for part two; Grinding and stock removal. until then, enjoy, and hopefully this has been helpful to you in your smithing endeavors.



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    12 Discussions

    I find that most files have too high of a carbon content to actually be functional as knives, but they make great conversation pieces! When you quench a high carbon steel that is as thin (or thinner) as a file the quench needs to be slow and EVENLY controlled. Water or brine quench is a crack waiting to happen; hot motor oil is better, but ambient air is probably going to leave it plenty hard enough to keep an edge.

    Generally, the heat treat process is always Harden, then Temper!

    1 reply

    I do 3 anneals and 5 heat treats, always quench mine in motor oil. On this piece its going to be a skinning knife. since its not going to be used for impact in any way, shape, or form i mainly desire a superhard edge so i dont waste time sharpening whilst skinning deer or elk.


    7 years ago on Introduction

    I've found that you should grind the ridge off the file before forging because it cracks along the ridgelines when quenched.

    4 replies

    Reply 6 years ago on Introduction

    Did you quench it in oil or water?
    High carbon steel like files should be quenched in oil, and tend to crack in water.
    Any used motor oil should work.


    Reply 6 years ago on Introduction

    Quenched in oil, Just wanted dome of the rasp details to show. Went through 3 rasps before I got one to quench wthout crackiing.

    The Metal Onehjjusa

    Reply 7 years ago on Introduction

    it was a rather fine-toothed file, so it didnt crack on me when i forged it. when i use rasps and double-cut files i do pre-grind to prevent that.

    No coal? No problem!
    Use lump charcoal.It's cheap, easy to light, burns hot, readily available and you can make it yourself.
    Google it to find out more.

    3 replies