Description Male Screw Nipple, M22M to 1/4â Male NPT. Used anywhere high pressure connections are frequently assembled and disassembled, in combination with screw couplers. Connects to all of the most common pressure washer equipment in the industry. Connects to female 1/4â fittings and converts M22 metric thread size to standard thread size. 300Â F and 5,800 PSI.