Flanged Fittings come in a variety of materials and head styles making it an optimal choice for standard 1/4-28 or M6 Flat-Bottom ports. Most of our Flanged Fittings are made of versatile Delrin which is manufactured to resists cross threading or loosening during use which delivers excellent dimensional stability. We also offer the Fittings in TEFZEL (ETFE) which is ideal for use in chemically aggressive environments. It includes a compatible stainless steel washer.