Name of tool steel materials T8Mn: T8Mn 
 Performance and use with T8 and T8A similar hardenability better, larger cross-section can be used in the manufacture of tools. 

 ● Delivery status: Delivery of steel in the annealed condition. By mutual agreement, can not annealed state delivery. 
 T8MN tool steel 
 [1] 
 Chemical composition: 
 Carbon C: 0.80 ~ 0.90 Si Si: ≤ 0.35 Manganese Mn: 0.40 ~ 0.60 S S: ≤ 0.030 P P: ≤ 0.035 Chromium Cr: to allow the residual content of ≤ 0.25, ≤ 0.10 (when the manufacture of lead-bath hardening steel) Ni: to allow the residual content of ≤ 0.20, ≤ 0.12 (when manufacturing lead bath hardening steel) Copper Cu: to allow the residual content of ≤ 0.30, ≤ 0.20 (when manufacturing lead bath hardening steel) Note: to allow the residual content of Cr + Ni + Cu ≤ 0.40 (manufacturing lead bath When quenching steel) [2] 
 Physical properties 
 Hardness: Annealed, ≤ 187HB, indentation diameter ≥ 4.40mm; quenching, ≥ 62HRC [3] heat treatment specifications: the sample quenching 780 ~ 800 ℃, water-cooled.