Alloy steel made American standard UN/UNC/UNF/UNEF/UNS 1/2"-12/13/14/16/18/20/24/27/28/32/36/40 TPI manual dies for DIY metal threads making. Specification: American standard Head diameter: 1/2" TPI:12/13/14/16/18/20/24/27/28/32/36/40 are vailable. ...