321/321H Stainless Steel
Seamless and Welded Pipes ASTM A312, A358, A213, A269, A270 ... The main variant of 321 is 321H which contains a higher quantity of carbon. 321 may contain up to 0.08% while 321H must contain between 0.04% and 0.08% carbon. The higher quantity of carbon confers greater strength at elevated temperatures. It is often chosen over Type 304 for its ...