STAINLESS STEEL ADAPTERS NPT FEMALE X BSPP MALE Take the challenge out of connecting different thread styles! These high quality 304 SS adapters will convert BSPP (British Standard Thread) to NPT (National Pipe Thread). WITH SEALING WASHERS: When tightened, these zinc-plated steel washers with Buna-N seals form a tighter grip than rubber and metal sealing washers. The Buna-N seal offers excellent abrasion resistance and good oil, weather, and chemical resistance. . FYI: When using stainless steel adapters with other stainless steel fittings or piping, you must use pipe dope or anti-seize tape to keep the stainless steel from galling or locking up.