Connection standard
M22 x 1.5, 14 mm: identify it, seal it, adapt it
How to recognize an M22 fitting with a 14 mm stem, why it leaks in a 15 mm bore, which makers state 14 mm, and the adapters sold for it.
Also listed as M22-14, M22-14mm, M22x1.5 - 14mm, M22 14 mm
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Short answer
M22 x 1.5, 14 mm is a metric thread, 22 mm across with a 1.5 mm pitch, whose inner stem is 14 mm. It shares its outside thread with the 15 mm version, so the two screw together, but AR Blue Clean says a 14 mm stem in a 15 mm bore will leak. Measure the inner bore of the male fitting or read the maker's documentation; Active (Active 2.0), Flexzilla (its pressure washer hoses) and Westinghouse (the PWEXT wand inlet) state 14 mm. More in M22 14 mm vs 15 mm.
What fitsAll 4 items that fit
- M22 14 mm hoseFlexzilla HFZPW3425M pressure washer hose, 1/4 in x 25 ft, M22 (14 mm stem)Check price on Amazon
- M22-14 mm quick-connect kitWestinghouse WPWFIT2KIT 4‑piece M22‑14 mm hose/gun quick-connect kit, brassCheck price on Amazon
- Extension wand, M22-14 inletWestinghouse PWEXT extension wand kit for pressure washers, 4,000 PSI, 4 GPMCheck price on Amazon
Key facts
- How to recognize it
- On a disconnected, depressurized part only: measure the inner bore of the male M22 fitting, which AR Blue Clean calls the most accurate method, or check the maker's documentation for the internal diameter[1][2]Depressurize as the machine's manual says first. AR gives no measurement tolerance.
- Thread
- M22 x 1.5: metric, 22 mm nominal outside diameter, 1.5 mm pitch; Swagelok lists a nominal male thread diameter of 21.85 mm. Westinghouse labels a 14 mm part 'M22x1.5 - 14mm'[3][4][1]The 14 mm is the inner stem, not the thread and not the hose's inside diameter.
- How it seals
- On an O-ring, not the thread: Swagelok says straight threads seal with a gasket, O-ring or metal contact, so sealant is not required or recommended. O-ring sizes are set per part: ProPulse lists 14 mm OD x 10 mm ID x 2 mm for its UberFlex (M22, bore not stated); Champion's 100384 parts list shows 14 x 9 x 2.5 mm[3][5][2]These O-ring sizes belong to those parts only.
- Male and female ends
- Both genders carry the size: AR Blue Clean describes gas hoses with a 14 mm female connection, and Westinghouse's PWEXT has a male M22-14 inlet[6][4][1]AR measures the bore on the male end.
- Where makers use it
- Makers that state 14 mm: Active (Active 2.0 hose and gun connections), Flexzilla (all eight pressure washer hose SKUs, 14 mm stem), Westinghouse (PWEXT wand inlet). AR Blue Clean's general observation: 14 mm is common on aftermarket hoses and gas pressure washers[7][8][4][1]AR names no models; its observation does not set the bore of any brand or model.
- Adapters makers sell
- AR Blue Clean PW554-B: 15 mm M22 swivel inlet to male M22 x 14 mm outlet. MTM Hydro: RSK 14 mm adaptor kits in stainless steel or brass, and an M22 plug (14 mm) x 3/8 in stainless QC coupler[6][9]AR lists no pressure rating for the PW554-B; MTM's collection page shows no ratings.
- Ratings on parts
- Flexzilla 14 mm hoses: 3,100 to 4,000 PSI maximum working pressure at 70°F, by SKU. Westinghouse PWEXT (M22-14 inlet): 4,000 PSI maximum. AR PW554-B: no rating listed[8][10][6]Flexzilla gives no burst rating or maximum water temperature.
- Common mix-ups
- M22 15 mm: same outside thread, so it screws on, but AR Blue Clean says a 14 mm stem in a 15 mm bore will leak and a 15 mm stem will not fit into a 14 mm bore[1]
- Not confirmed
- Not confirmedNo source gives a bore tolerance. Many M22 parts state no bore: Kärcher's M22 guns, SIMPSON's MorFlex hoses and MSH3125 parts, ProPulse's UberFlex, and Westinghouse's 'M22 Quick-Connect' on the ePX3500.
Watch out for
- Never force a 15 mm stem into a 14 mm bore, or tighten a 14 mm stem harder to stop a leak in a 15 mm bore; AR Blue Clean warns against forcing mismatched connections.
- Westinghouse's PWEXT manual tells users to put thread seal tape on that kit's inlet threads. That is Westinghouse's instruction for its kit; Swagelok says straight threads seal on the O-ring and need no sealant.
- Work only on a disconnected, depressurized fitting: see injection injuries and depressurizing first.
- AR's '14 mm on gas machines' is a generalization; only a maker document tells you a given model's bore.
What fits
Product details below are the seller's own description unless a source is shown. Pick the variant named for each item.
M22 14 mm hose
Flexzilla HFZPW3425M pressure washer hose, 1/4 in x 25 ft, M22 (14 mm stem)Choose the 1/4 in x 25 ft HFZPW3425M.
Flexzilla states M22 fittings on a 14 mm stem. Check that your machine's ports are 14 mm too.
M22-14 mm quick-connect kit
Westinghouse WPWFIT2KIT 4‑piece M22‑14 mm hose/gun quick-connect kit, brassChoose the 4-piece WPWFIT2KIT (one hose fitting, three gun fittings).
Westinghouse lists it for M22-14 mm accessories on its ePX and WPX machines. It states no pressure rating.
14 mm to 15 mm adapter
Sun Joe SPX‑M22M2F 14 mm M22 male to 15 mm M22 female high-pressure hose adapter, brassChoose the SPX-M22M2F (14 mm male to 15 mm female).
Sun Joe lists a 14 mm M22 male end and a 15 mm M22 female end. It states no pressure rating.
Extension wand, M22-14 inlet
Westinghouse PWEXT extension wand kit for pressure washers, 4,000 PSI, 4 GPMChoose the PWEXT extension wand kit.
Westinghouse states a male M22-14 inlet and a 4,000 PSI maximum.
Questions
How do I tell if my M22 fitting is 14 mm or 15 mm?
AR Blue Clean says to measure the inner bore of the male M22 connection, the most accurate method, or check the product documentation for the internal diameter. Do it only on a disconnected, depressurized part.[1]
Will an M22 14 mm hose work on a 15 mm outlet?
It will thread on, because the outside threads match, but AR Blue Clean says a 14 mm stem in a 15 mm bore will leak. Use a part or adapter whose maker states the right size.[1]
Should I put thread tape on an M22 fitting?
Swagelok says straight threads seal with a gasket or O-ring, so sealant is not required or recommended on them; M22 seals on its O-ring. Westinghouse's PWEXT manual is an exception for that kit's inlet thread. Champion says to replace damaged O-rings rather than seal a leak.[3][4][2]