Learn to Turn, 3rd Edition Revised & Expanded. Bradley Richardson

      Recycled Steel

      High-quality steels can be expensive. This is why most knifemakers start out in the scrapyard. You can save a lot of money scrapping for steel, but you can’t always be certain of the quality that you’re getting. I’ve picked up a few tricks that are very helpful when choosing recycled steel.

      MAGNET TEST

      The first thing you want to verify is that your steel is indeed steel. Some alloys such as zirconium and nickel silver may come across as steel even though they aren’t. A quick way to solve this problem is by using a magnet. If it sticks, then it’s steel.

      Grinding high carbon steel will result in a much brighter display of sparks that feature more branches and veins that a mild steel would.

      SPARK TEST

      Now that you have a piece of steel, you’ll want to check its carbon content. If it’s the frame of your bike, I’ll tell you now that it’s probably mild steel, but if it’s the chain or the gears, you may be in luck. When looking for scrap steel, keep an eye out for tools such as files or pry bars and moving parts such as axles or springs. You can check for carbon content by using the spark test. The spark test isn’t a foolproof method, but it generally works. Steel with higher carbon content will display more forks and branches in their sparks when held to a grinder. Those with lower carbon contents will display much smaller sparks that are not as bright.

      Mild steel offers a much less impressive display of sparks.

      HARDNESS TEST

      The final test that I like to do is a hardness test. You can do this by heating the steel up to above its nonmagnetic temperature, which is around 1420°F (771°C) for most carbon steels or until it is a yellow-orange color and then quenching it into oil. You can then try cutting into the steel with a file. If the steel has been properly hardened, the file should skate off without removing any material.

      You’d be surprised at how many scrap items can be repurposed into knife blades.

      I’ve seen blades made from hand files, leaf springs, lawnmower blades, railroad spikes—you name it. Using recycled steel is a way to tinker around without losing much money on material costs. It can also be a great way to “breathe new knife” into an old piece of junk!

      This knife was made from an old file.

      You’d be surprised at how many scrap items can be repurposed into knife blades. Lawnmower blades and hand files will both hold a great edge when heat treated properly. Rebar or railroad spikes are hit or miss. Springs or bearings are great choices for knife steel because they are designed to flex and undergo routine pressure and movements that require the steel to be accurately tempered. I also keep some mild steels on hand that are great for practicing techniques or creating jigs.