200 pounds of 4340 steel in an annealed state (ready for easy cutting) new condition still in the packaging! It’s very rare to find metal precisely labeled at the scrap yard, knowing exactly what metal this is opens up all sorts of options!

Ni 1.82%, Cr 0.50% to 0.80%, Mo 0.25%, C 0.40%  Atlas4340

This can be hardened to 58 HRC with water quench! For an extremely break resistant steel this is a very high hardness level. After a water quench and a 450F heat treating the blade edges should retain a hardness of about 52-55 HRC. The properties of this alloy should allow me to differentially temper blades to the same extent as 1080 high carbon steel would, but without the lesser impact resistance to breaking. I’m thinking about 55 HRC on the edge, 35-40 HRC on the back. This steel is really good stuff. Any blade made with it will be as strong as a pry bar with an edge almost as keen as the steel used on the edges of Japanese swords.

This is a very tough, very abrasion resistant & corrosive resistant steel alloy with enhanced hardenability properties. The 0.40% carbon places it on the very bottom end of the high carbon steels – meaning it can be hardened but normally not to a degree that higher carbon content high carbon steels can(1060-1095) – but the alloys in it will allow it to harden to a much greater degree than standard 1040 carbon steel AND have the extra toughness and abrasion resistance inherent in this alloy. It’s basically super powered 1040 high carbon steel. All for the same price by weight as rusty rebar (30 cents/lbs) LOL! What a great find!!

Check out the properties of 4340 vs 1095…..

Vastly superior hardness, tensile strength and yield strength.

From http://www.makeitfrom.com/compare-materials/?A=Annealed-4340-Ni-Cr-Mo-Steel&B=SAE-AISI-1095-SUP4-1.1274-C100S-G10950-Carbon-Steel