Friday, March 15, 2019

Steel: What Kind and From Where?

Steel isn't hard to find, generally not expensive, and you can do lots of things with it. But what kind do you use, and where do you find it, once you’ve decided on a project for it?

Mild Steel
For a lot of things (basic ironwork, braces, learning the art of forging) you can use mild steel. This is a basic steel, composed of iron and up to 0.2% carbon. It’s used in rebar (the bar with a textured surface used to reinforce concrete), angle iron, steel straps of many sizes, and lots of other things that require the strength of steel but don't need to be flexible or hold a cutting edge. You can get it at a salvage yard, or if you need a particular size (width, thickness, shape) you can call steel companies and see if they have it.

If you want to try to grind or forge cutting tools, keep it simple in the beginning. That means using a steel with at least 0.6% carbon, but not a highly-alloyed type that requires intricate heat treatment. There are two I recommend for this task: 5160 and O1.

Both of these types of steel are oil-hardening steels [which means that the alloy is heated and then quenched in oil], and people have used vegetable oil, commercial heat-treating oil (there are different types for different steels), and 5-weight motor oil. Both types need to be quenched to harden from a critical temperature of 1500º F (which can be reached in a charcoal or coal fire, or in a small fire-brick enclosure using a couple of torches), and can be tempered, depending on intended use, at anywhere from 375-500º F. Neither requires the very high and ‘must be just right’ temperatures of stainless or the highly alloyed steels, and they also temper at lower temperatures, In fact, you can do the tempering in a kitchen oven*.

5160 Steel
5160 steel can be found all over, as it’s used to make leaf and coil springs for car and truck suspensions. It can be found in many sizes as well; hit a salvage yard and you can get it for scrap price, which was around $0.20/lb the last time I bought some (prices will vary). The carbon content for this steel is 0.6% and you can use it for chisels, knives, swords, and springs. It’s really good for bigger knives that will be used for heavy cutting or chopping, but it will work well for a small knife as well.

O1 Steel
O1 is a high-carbon tool steel. It’s best to order/purchase this from an industrial supply so you know exactly what you’re getting; it’s also sold as “oil-hardening drill rod.” It’s not as good for big, heavy cutting blades, but is truly excellent for other knives and chisels.

Generic Medium-Carbon Steel
That’s steel for large projects addressed, but what about for small? Perhaps you need something with which to make a small flat or v-shaped spring intended for light duty?

Take a look around the hardware store, or someplace construction is being done. See that thin steel strap they wrap bundles of brick and such with? That just might work, as might a worn-out hacksaw blade. I’ve known of people making a new magazine spring for a bolt-action rifle using these.

One more source for small medium-carbon stock, good for springs and flint strikers and the like: overhead garage door springs. It's really handy, and you can often get a piece of a broken one for free (or at least cheap) from companies that install and maintain the doors.

*Make sure you clean all the quench oil off first; it smells bad if you don’t.

No comments:

Post a Comment

The Fine Print

This work is licensed under a Creative Commons Attribution- Noncommercial- No Derivative Works 3.0 License.

Creative Commons License

Erin Palette is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to