threading dies Ridgid type, ranging from 1/2"-4" BSPT & NPT avaliable special type at request use with threading machine threading diesSpecial forged pipe threading diessizes:1/2"-3/4", 1"-2", 2 1/2"-3", 2 1/2"-4"*ISO threads (Metric) M12-M52 (need additional die head)material:alloy, specific alloy (9CrSi), HSS, high grade HSSthreads type:BSPT , NPT, ISO(M12-M52)