T12 

 T12 high-carbon steel because, after quenching have more excess carbon, produced by abrasion resistance and hardness are not suitable for shock load, cutting speed is not high, constant heat cutting edge tools, such as the production lathes, planer for turning, milling, drilling; can be made reamers, reamer, tap, die, blade, gauge, cut tobacco knife, rasp, and the section size small cold trimming die, punching die and so on. 
 The chemical composition of T12 
 T12 steel chemical composition (GB1298-86) w /% C Si Mn SP 
 1.15 ~ 1.24 ≤ 0.35 ≤ 0.40 ≤ 0.030 ≤ 0.035 

 T12 thermal processing 
 T12 steel without thermal processing temperature of the heating projects / ℃ start temperature / ℃ termination temperature / ℃ cooling 
 Ingot 
 Billet 1100 - 1150 
 1050 ~ 1100 1050 ~ 1100 
 1020 ~ 1080 850 ~ 750 
 800 ~ 750 700 ℃ after the cold sand 
 700 ℃ after slow cooling 
 Note: Do not heat too long holding time to prevent decarburization; become useful when the temperature is not high the last fire, 700 ℃ prior to rapid cooling, in order to avoid mesh carbide precipitation; 700 ℃ after, should slow cooling to avoid thermal stress generated due to crack.