SINODRILLS DTH Accessories We also manufacture various accessories to meet comprehensive of requirement, which consists of sub adapters and wrenches that are made of superior alloy steel. Sub adapters: Pin-Box type, Pin-Pin type, Box- Box type; Thread: 2 3/8 API REG, 2 7/8 API REG, 3 1/2 API REG, 4 1/2 API REG, 2 3/8 API IF, 2 7/8 API IF, 3 1/2 API IF, etc. Wrenches:28mm, 40mm, 57mm, 65mm, 75mm, 95mm, 102mm, 120mm and 140mm wrench. We also manufacture the break-out hydraulic bench wrench.