Tool · Couplers, adapters and swivels
Pressure washer fitting identifier
Pick the fitting you see to learn how to confirm it, its thread, how it seals, its male and female names, where makers use it and the adapters makers sell for it.
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Short answer
Pick the fitting you see to learn how to confirm it, its thread, how it seals, its male and female names, where makers use it and the adapters makers sell for it. Confirm by measuring the part itself, disconnected and depressurized, and treat chart values as identification aids.
Picks this tool points toSee the shortlist
- M22 x 1.5, 14 mm
- M22 x 1.5, 15 mm
- 3/8 in quick-connect
- 1/4 in quick-connect
- NPT (tapered pipe thread)
- BSPP and BSPT
- Garden-hose thread (GHT)
- Kärcher bayonet and Kärcher quick connect
Choose your connection standard to see the key facts and what fits. Each fact links to its source on the full page.
What the table shows
| Connection standard | How to recognize it | Thread | How it seals | Male and female ends |
|---|---|---|---|---|
| M22 x 1.5, 14 mm | 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 | 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' | 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 | 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 |
| M22 x 1.5, 15 mm | 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) | M22 x 1.5: metric, 22 mm nominal outside diameter, 1.5 mm pitch, the same outside thread as M22 14 mm | On an O-ring: Swagelok says straight threads seal with a gasket, O-ring or metal contact, and sealant is not required or recommended | 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 |
| 3/8 in quick-connect | On a disconnected, depressurized part only: two halves, a plug (Dixon calls it a nipple) and a coupler with a sliding sleeve or collar. Champion's 100386 pump outlet is a female quick connector with a sliding metal collar that takes the hose's male end | None at the joint. A plug or coupler often has a pipe thread behind it: MTM lists 3/8 in MPT and FPT couplers | Dixon's industrial couplings hold the halves with locking balls under the coupler sleeve and seal with O-ring and valve seals | Male plug and female coupler (socket). SIMPSON's 41028 has a 3/8 in male QC plug on one end and a female QC socket on the other; DEWALT's DXPA50PH has 3/8 in one-piece QC socket and plug fittings |
| 1/4 in quick-connect | On a disconnected, depressurized part only: the small push-in coupler at the end of the wand or lance, which nozzles and attachments plug into (for example SIMPSON's 16 in MSH3125 lance and RYOBI's RY1419MT wand) | None at the joint. Behind it there may be a pipe thread: MTM's PRIMA by Veloci couplers and plugs come in 1/4 in MPT and FPT versions, and MTM's SGS28 gun has a 1/4 in FPT outlet | Dixon's industrial quick couplings seal with O-ring and valve seals | RYOBI lists a 1/4 in quick-connect nozzle coupler on the RY1419MT wand; MTM's PF22.2 foam cannon kit adds a 1/4 in plated-steel QC plug, and MTM says some residential washers need its separately sold Low Profile QC plug (24.5006) |
| NPT (tapered pipe thread) | On a disconnected, depressurized part only: measure the diameter at the start and end of the thread with calipers (a tapered thread gets smaller, Dixon says), then find the pitch: 1/4 and 3/8 in NPT have 18 threads per inch | Tapered pipe thread, 60-degree thread angle, taper 1 degree 47 minutes; 18 TPI at 1/4 and 3/8 in. ASME B1.20.1 is the US standard. In '1/2-14 NPT', 1/2 in is the nominal pipe inside diameter and 14 is threads per inch | On the threads: Swagelok says tapered pipe threads seal on the threads and always need a sealant | FPT is female pipe thread and MPT male. Suttner lists most of its guns with a 3/8 in FPT inlet and a 1/4 in FPT outlet; MTM's SGS28 has a 3/8 in FPT inlet with a live swivel and a 1/4 in FPT outlet. Dixon says female NPT is not available on hose swivel nuts |
| BSPP and BSPT | On a disconnected, depressurized part only: measure the diameter at both ends of the thread to tell tapered from parallel (Dixon), then the pitch: 1/4 and 3/8 in BSPT have 19 threads per inch (Swagelok) | Both have a 55-degree thread angle. BSPT (ISO 7/1) is tapered at the same 1 degree 47 minutes as NPT; BSPP (ISO 228/1) is straight | BSPT seals on the thread and always needs a sealant, like any tapered pipe thread; BSPP is straight and seals with a gasket, O-ring or metal contact, so sealant is not required or recommended | Cat Pumps lists its 7265 turbo nozzles with a 1/4 BSP(F), a female BSP inlet |
| Garden-hose thread (GHT) | On a disconnected part with the water off: measure the male thread's outside diameter with a caliper or O.D. tape; Dixon lists 3/4 in GHT at 1.0625 in | 3/4 in GHT: 1.0625 in male outside diameter, 11-1/2 TPI (Dixon). ASME B1.20.7 covers hose coupling threads in nominal sizes from 1/2 to 4 in | Not confirmed | Not confirmed |
| Kärcher bayonet and Kärcher quick connect | On a disconnected, depressurized part only: the hose clicks into the gun and machine through a Kärcher-specific quick connect, and the wand locks into a Kärcher bayonet on the gun | Not confirmed | Not confirmed | Hose end: Kärcher-specific quick connect, with an adapter that clicks in and out of the machine and gun. Wand end: Kärcher bayonet |
Each standard's page adds where makers use it, the adapters makers sell, ratings seen on parts and the common mix-ups. Every value is attributed to a maker, distributor or standards body.
How to identify a thread
Swagelok's thread identification procedure has five steps:[1]
- Decide whether the thread is tapered or straight.
- Measure the diameter.
- Find the pitch.
- Determine the thread standard.
- Identify the end connection.
For the first step, Dixon suggests measuring the diameter with calipers at both the start and the end of the threads; a tapered thread gets smaller along its length.[2] Dixon says to measure a male thread's outside diameter with a caliper or O.D. tape, and that for non-metric threads the pitch is expressed as threads per inch.[2]
M22: measure the bore
An M22 thread alone does not tell you which M22 you have. AR Blue Clean recommends identifying an M22 fitting by measuring the inner bore of the male M22 connection, or by checking the product documentation for the internal diameter.[3] The M22 14 mm vs 15 mm guide explains why the bore matters.
Measurements and charts
Dixon notes that measured thread values may differ slightly from the values in its size charts.[2] Swagelok also says its tables are identification aids, not inspection criteria, and that even experienced workers sometimes have difficulty identifying threads.[1] If you are between two standards, the maker's document for the part settles it.
Measure only a depressurized part
Champion's manual says to depressurize by engaging the trigger lock, turning the unit off, shutting off the water, then releasing the latch and squeezing the trigger, and never to disconnect the high-pressure hose while the system is pressurized.[4] Follow your own machine's manual, then disconnect the part before you measure it.
Next
- M22 x 1.5, 14 mm
- M22 x 1.5, 15 mm
- 3/8 in quick-connect
- 1/4 in quick-connect
- NPT (tapered pipe thread)
- BSPP and BSPT
- Garden-hose thread (GHT)
- Kärcher bayonet and Kärcher quick connect
Choose your connection standard to see the key facts and what fits. Each fact links to its source on the full page.
Shop what this tool points toSee the shortlist
Questions
How do I tell M22 14 mm from 15 mm?
AR Blue Clean recommends measuring the inner bore of the male M22 connection or checking the product documentation for the internal diameter. It gives no tolerance figure.[3]
How do I know if a thread is tapered?
Dixon suggests measuring the diameter with calipers at both the start and the end of the threads. A tapered thread gets smaller along its length; a parallel one stays the same.[2]