1898 L.C. Smith No. 00 Armor Steel was Rephosphorized and Resulfurized AISI 1045 Low Alloy Carbon Steel with a tensile strength of 101,000 psi

c. 1925 Crescent Fire Arms Genuine Armory Steel with LLH mark was Rephosphorized AISI 1040 Low Alloy Carbon Steel with a tensile strength of 104,000 psi

Industry standard for AISI Chrome Moly 4140 is 95,000 - 100,000 psi

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