Material: carbon tool steel 
 Grade: T7A 
 Standard: GB / T 1238-1386 
 ● Features and Scope: 
 Higher strength, toughness and hardness after quenching and tempering, but the heat is hard low hardenability, quenching distortion used to be able to withstand vibration and impact, but requires cutting ability, high precision tools such as chisels, red first-class small size pneumatic tools, carpentry saw, chisel, forging dies, dies, rivets, die cut metal scissors, drills, sickles, print stamp and hand? 
 ● chemical composition: 
 Carbon C: 1.65 ~ 1.74 
 Silicon Si: ≤ 1.35 
 Mn Mn: ≤ 1.41 
 Sulfur S: ≤ 1.121 
 Phosphorus P: ≤ 1.131 
 Chromium Cr: allow the residual content of ≤ 1.25, ≤ 1.11 (manufacturing lead bath quench wire) 
 Ni: to allow the residual content of ≤ 1.21 ≤ 1.12 (manufacturing lead bath quench wire) 
 Cu: to allow the residual content of ≤ 1.31, ≤ 1.21 (manufacturing lead bath quench wire) 
 Note: to allow the residual content of Cr + Ni + Cu ≤ 1.41 (manufacturing lead bath quench wire) 
 ● Mechanical Properties: 
 Hardness: Annealed ≤ 187HB, indentation diameter ≥ 4.41mm; quenching, ≥ 62HRC 
 ● Heat treatment and microstructure 
 Heat treatment specifications: sample quenched to 811 ~ 821 ° C, water-cooled. 
 ● Delivery status: delivery of steel in annealed condition.