Connection standard
M22 x 1.5, 15 mm: why it will not take a 14 mm part
The M22 15 mm fitting: why a 15 mm stem will not enter a 14 mm bore, the adapters makers sell between the two, and what no source says about who uses 15 mm.
Also listed as M22-15, M22-15mm, M22 15 mm
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Short answer
M22 x 1.5, 15 mm has the same 22 mm, 1.5 mm pitch outside thread as the 14 mm version but a 15 mm inner stem. AR Blue Clean says a 15 mm stem will not fit into a 14 mm bore, and a 14 mm stem in a 15 mm bore leaks. AR's general observation is that many electric washers and their accessories use 15 mm, but it names no models, so measure your part. Adapters with both bores named come from AR Blue Clean, MTM Hydro and DEWALT.
Key facts
- How to recognize it
- On a disconnected, depressurized part only: measure the inner bore of the male M22 fitting or check the maker's documentation for the internal diameter (AR Blue Clean)[1]AR gives no measurement tolerance.
- Thread
- M22 x 1.5: metric, 22 mm nominal outside diameter, 1.5 mm pitch, the same outside thread as M22 14 mm[2][1]
- How it seals
- On an O-ring: Swagelok says straight threads seal with a gasket, O-ring or metal contact, and sealant is not required or recommended[2]
- Male and female ends
- AR Blue Clean describes the 15 mm male connection found on many electric washers, and its PW554-B has a 15 mm M22 swivel inlet. MTM sells an M22 female 15 mm twist coupler[3][4]'Many' is AR's word; check the specific machine.
- Where makers use it
- AR Blue Clean's general observation: many electric pressure washers and their accessories use 15 mm. DEWALT's DXPA25PH hose includes a 14/15 mm M22 connector[1][5]No maker document read assigns 15 mm to a named machine.
- Adapters makers sell
- AR Blue Clean PW554-B (15 mm swivel inlet to 14 mm male outlet); MTM SRG 15 mm adaptor kits in stainless steel or brass, and an M22 female 15 mm twist coupler x 3/8 in stainless QC plug; DEWALT's 14/15 mm M22 connector with the DXPA25PH hose; an M MINGLE brass adapter, female M22 14 mm to male M22 15 mm, sold by PWaccs[3][4][5][6]The M MINGLE adapter has no maker documentation; its figures are the seller's.
- Ratings on parts
- DEWALT DXPA25PH (with its 14/15 mm connector): 3,700 PSI, cold water only. M MINGLE adapter: 4,500 PSI maximum, as the seller lists. AR PW554-B: no rating listed[5][6][3]
- Common mix-ups
- M22 14 mm: the threads match, but AR Blue Clean says a 15 mm stem will not fit into a 14 mm bore and a 14 mm stem in a 15 mm bore will leak[1]
- Not confirmed
- Not confirmedWhich named machines use 15 mm (no maker document read states it); bore tolerance; ratings for the AR and MTM adapters.
Watch out for
- AR's 'many electric washers use 15 mm' is a generalization; it does not tell you any one model's bore.
- The M MINGLE adapter's 4,500 PSI is the seller's figure (PWaccs); no maker documentation was found.
- AR lists no pressure rating for the PW554-B and tells buyers to check their hose's pressure rating.
- Never force a 15 mm stem into a 14 mm bore; AR Blue Clean warns against forcing mismatched connections.
What fits
Product details below are the seller's own description unless a source is shown. Pick the variant named for each item.
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 15 mm M22 female end and a 14 mm M22 male end. It states no pressure rating.
Questions
Will a 15 mm M22 stem fit a 14 mm bore?
No. AR Blue Clean says a 15 mm stem will not fit into a 14 mm bore, even though the outside threads are the same.[1]
Which adapter joins a 14 mm hose to a 15 mm machine connection?
AR Blue Clean says its PW554-B lets a gas hose with a 14 mm female connection attach to the 15 mm male connection found on many electric washers. AR lists no pressure rating for it, so check your hose's rating. See adapters between M22 and quick-connect.[3]
Do electric pressure washers use 15 mm M22?
AR Blue Clean says many electric pressure washers and their accessories use 15 mm, but that is a general observation with no model list. Check your machine's documentation or measure the bore.[1]