Our Flanged Fitting is made from versatile Delrin. Our versatile Delrin nut resists cross threading or loosening during use delivering excellent dimensional stability It includes a 316 stainless steel washer. This fitting is compatible with a 1/4-28 Flat-Bottom port geometry. Our Delrin fitting has a 5/16 Standard Knurl Head style and is for is for 1/16OD Tubing. It comes is blue, black, Cream, green, Red, white and in TEFZEL (ETFE).