SEAMLESS GALV NIPPLE 6X6|BeckĀ® steel pipe nipples and steel pipe couplings are manufactured in accordance with the ASTM A733 Standard Specification for welded and seamless carbon steel and stainless steel pipe nipples. Steel pipe couplings are manufactured in accordance with the ASTM A865 Standard Specification for threaded couplings, steel, black or zinc-coated (galvanized) welded or seamless, for use in steel pipe joints. Beck API couplings are manufactured in accordance with the API Specification for line pipe.