The Scrapyard Steel Guide — Find and Identify Free Steel

There's four hundred dollars of knife steel in a junkyard near you. It's priced as scrap.

Steel is the running cost that quietly ends most blacksmithing hobbies. You build the forge once — but bar stock is forever. You order some, use it up, order more, and about six months in you total it up and stop.

The way out is old and unglamorous: almost every smith who works regularly gets a meaningful share of their material out of scrap. The catch is that scrap doesn't come labelled. A leaf spring, a length of rebar and an old file look broadly similar in a pile and behave completely differently under a hammer.

This guide closes that gap.

What's inside

• Where the steel is — scrap yards, vehicle repair shops, farm and estate sales, and how to approach each so you're welcome back.
• Three tests you can do today — the file test, the spark test with a full pattern reference table, and the quench-and-break test that settles it.
• A source reference table — eleven common scrap sources, what each typically is, and what it's genuinely good for. Leaf springs, coil springs, files, bearing races, lawnmower blades, rebar, rail spikes and more.
• What to never put in the fire — galvanised steel, plated stock and coated unknowns, and why this section matters more than the rest.

Written as a working reference, not a lecture. Take the source table with you the first few times you go looking; after a dozen trips you'll stop needing it.

A note on scope. A practical starting point for hobby work, not a metallurgical reference. Scrap steel is by definition of unknown specification — material for structural, load-bearing or safety-critical use should be bought to a known spec rather than salvaged.