Ridgid® NPT Die is made of high speed stainless steel for enhanced durability. It is designed to use with black, galvanized/ plastic-coated pipe, 1/4 - 2" pipe at 36 RPM and 2 1/2 - 4" at 12 RPM, stainless steel, IMC and heavy-wall conduit, rod up to 30 rockwell C. It has an induction motor to identify the sound levels within the limit set by regulating authorities.