Flanged Fittings are and excellent choice for making flanged tubing conntections. They are compatible with most standard 1/4-28 or M6 Flat-Bottom ports. The hard, inert Delrin® (acetal resin) nut has been optimized to resist cross threading or loosening during use, while the TEFZEL™ (ETFE) nuts work well in chemically aggressive environments. Fittings for 1/16″ or 1/8″ OD tubing are supplied with a nut and a 316 stainless steel washer. There are multiple selections of head styles, materials, and colors to choose from.