Carbide API Threading Inserts are available in multi-tooth and single-tooth, with round and buttress threads available. As a professional supplier of ... . SMT carbide API threading inserts are in multi-tooth and single-tooth, round and buttress threads, 3,45,8,10 TPI ... for J55, L80, L80, and P110. Any special thread forms with drawings and samples are also welcome. For more information, you ...