This has probably been exhaustively covered, but a search for "fire steel" pulls up hundreds of posts. I was thinking of forging a couple of fire steels for flint-and-steel fire starting from cold rolled, but also have some of the ubiquitous Nicholson files in my stash.  What steels are optimum for this purpose and which might not work well at all? If you used an old file, who would you heat treat it?

A carbon steel with 50-60 points of carbon or above should work  Try 1095.  

 

I've made lots of fire strikers out of 1080 and/or 1095 and /or old files and a few from automobile coil springs. 

I have heard that some cheap files are only case hardened but have never come across one. 

It's easy to test a file to see if it will make a good fire steel. Give an edge or a corner a few good strikes with a sharp flint and see how good it sparks. If it doesn't throw good sparks then don't try to make a striker. 

This test will not work for brand new medium to high carbon steels because they are usually annealed when purchased. 

Heat treating a fire steel made from a file or any medium to high carbon steel is dirt simple. Heat it up until a magnet will not stick to it and quench it in oil.  Heating it hotter than the point where a magnet will not stick to is not needed and will add to the risk of cracking. 

 

 

Thanks fellas. Dick, I'll take your lead on this if I can just locate a better hand-cranked blower for my charcoal forge.

Blower substitute ?   Easy, just get hold of an electric hair drier or a bathroom exhaust fan and you have plenty of air blast for a charcoal forge. I assume you are talking about charcoal not charcoal briquettes. 

A double-action air mattress pump is a classic blower alternative, especially for charcoal.

Yes, talking about charcoal, not briquettes. My third Tim Lively washtub forge. I really hate to use power with this, and will continue my quest for an affordable Champion or Buffalo blower.  I tried one of those made-in-India blowers and it just doesn't put out the volume needed for my forge. Funny, they are all over Craigslists 500 or 1,000 miles from hear, but locally, nada. 

Was fun forges being longer trenches tend to take more air than a JABOD forge, but this is what I use on my mark III JABOD forge. 

I haven't used files for fire steels. Instead I use (horse drawn) dump rake tines for making both fire steels and small knives/letter openers. Junk yard steel chart lists them as 1090.

Can draw decent sparks using chert after a quench in water from orange heat and no tempering. But having read dickb's post, go with the magnet test (more accurate then eye) and quench. 

Attached are a couple of images. The tines are 5/16 inch dia.  Styles obviously differ with manufacturer. The square is 12 inches on the outside of the long arm.

 

I’ve made hundreds with O1steel, W1 Drill Rod, Old Nicholson files, 5160 leaf springs, and 1095. My favorite is W1 and O1!

I've also had very good luck with W1 square stock. It sparks like crazy. 

Generally, I've had good luck with garage door springs but experiment first.  There are some springs that have odd alloys that do not harden well. 

"By hammer and hand all arts do stand."

If you want a practical fire steel you don't want it too hard. You want a fat long lived low yellow spark, white sparklers don't last long enough for dependable lights.

Frosty The Lucky.

If it's too hard and dropped on a hard surface, it will break like glass. (ask me how I know).