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Quick answer
Pressure washers use two kinds of connection. M22 is a twist-on metric thread, 22 mm across, found on hoses, guns and wands. Quick connects push and lock: 1/4 inch at the wand tip for nozzles and 3/8 inch on hoses. M22 also comes with a 14 mm or 15 mm inner stem, and the two don't mix.
Replacement nozzles with 1/4-inch quick connect:
Simpson 80145 5-Nozzle Set Simpson 80143 Turbo NozzleThe fittings side by side
| Fitting | How it connects | Where you find it |
|---|---|---|
| M22-14mm | Twist-on collar, 22 mm thread, 14 mm inner stem | Kleen-Rite: most gas-powered and professional machines |
| M22-15mm | Twist-on collar, 22 mm thread, 15 mm inner stem | Kleen-Rite: common on consumer electric machines |
| 1/4-inch quick connect | Push in, collar locks it | Wand or gun tip: nozzles, foam cannons, surface cleaners |
| 3/8-inch quick connect | Push in, collar locks it | Hose to pump and hose to gun |
14 mm vs 15 mm: why it matters
Both M22 types have the same 22 mm outer thread, so they look alike. The difference is the stem inside that pushes into the O-ring. Kleen-Rite's fittings guide says you cannot mix M22-14mm and M22-15mm; the joint will leak or vibrate loose. It also says that if a manual lists M22 without an inner size, it's almost certainly 14 mm. Accessory makers usually state the size, for example SurfaceMaxx says its quick connect kit is M22-14mm.
How to tell which you have
- Check the manual or parts list for "M22-14" or "M22-15".
- Look at the connection: a threaded collar you twist is M22. A collar you pull back to release is a quick connect.
- Nozzles: standard color-coded tips, like Simpson's 80145 set, have 1/4-inch quick-connect plugs and need a 1/4-inch coupler at the wand tip.
Adapters
To add quick connects to an M22 machine, you need an adapter with the right M22 stem size on one end and the quick connect size on the other. Kleen-Rite says to check that each adapter matches your machine's PSI rating, thread type, connection size and sealing style.
Release the pressure before you unscrew anything. Kleen-Rite says to turn off the machine, shut off the water and release trapped pressure before installing or removing fittings. Simpson's manual has you squeeze the trigger to do that.
How we work: fitting sizes come from Kleen-Rite's fittings guide (a pressure washer parts retailer) and SurfaceMaxx support. Nozzle specs come from Simpson. Sources are listed below.
Questions people ask
What's the difference between M22 14mm and 15mm?
Both use a 22 mm thread. The inner stem is 14 mm or 15 mm. Kleen-Rite says you can't mix them, and that 14 mm is standard on most gas and professional machines.
What size quick connect do pressure washer nozzles use?
Standard color-coded tips use a 1/4-inch quick-connect plug at the wand tip. Hoses usually use 3/8-inch quick connects.
How do I know if my washer is M22 14mm or 15mm?
Check the manual or parts list. Kleen-Rite says if a manual lists M22 without an inner size, it's almost certainly 14 mm.
Sources
Last checked Oct 23, 2026. Pressure washer spray can cause injection injuries. Lock the trigger before changing tips and release the pressure before disconnecting anything, as Simpson's manual says.
