... tooling solution to oil and gas industry at home and abroad for many years. SMT carbide API threading inserts are ... in multi-tooth and single-tooth, round and buttress threads, 3,4,5,8,10 TPI available for ... forms with drawings and samples are also welcome. For more information, you are very welcome to contact ... e-mail. Twin-lock Multi-tooth Carbide API Inserts for couplings