All Penn Machine Nickel and Stainless Steel Alloys are processed as Low Melting Point Contamination Free Products as defined as materials not coming in contact with or being processed with low melting materials such as antimony, arsenic, bismuth, cadmium, lead, tin, phosphorous, sulfur, or zinc in excess of 250 ppm. Low melting point elements as stated are detrimental for cracking the metal at elevated temperatures. Penn Machine assures that we process our Nickel and Stainless Steel Alloys to be contamination free of such elements in our processing and manufacturing of supplied piping products.