We can offer square and hexagonal kellys,kelly’s are available up to 46 feet long. Our kellys are made from AISI 4142H-4145H modified alloy bars that are quenched and tempered full length. A hardness range of 285 to 341 BHN and a minimum impact ＆#118alue of 40ft-lbs are maintained one inch below the surface at room temperature. All ends and center drive sections-trepanned to provide true bores. They are drifted to API specifications, and all connections are machined. Kellys are stamped with the API monogram, where applicable.