Arntzen Corporation has 17 plate rolls of various sizes, this allows us to roll bend a broad range of shell & cone sizes. Material is cold formed in accordance with USC-79(d); after rolling Arntzen tack welds the joint seam to a prequalified weld procedure. We form many different grades of As-rolled and Normalized steel, the most common are SA516 Grade 70, SA36, SA387, SA537, SA240 304 SS, SA240 316 SS.