What conditions are required for cold-formed heads?

　　Cold-formed heads feature precise dimensions and stable quality, without surface roughness or oxidation caused by heating, and have a beautiful appearance. Also, there is no need to worry about material deterioration caused by heating. Five conditions for cold-formed heads:

　　① The medium used is extremely or highly hazardous;

　　② Materials required to undergo impact tests (judged in accordance with ASME V Ⅲ -1UCS-66);

　　③ Cold-formed steel plates with a thickness greater than 15.9mm;

　　④ Plates with a thickness reduction rate greater than 10% after cold forming;

　　⑤ Those with forming temperatures within the range of 120 to 482 ℃.