Guide · Trigger guns and short guns
Choosing a replacement pressure washer trigger gun
Match the gun's inlet to your hose, its outlet to your wand, and its PSI, GPM and temperature rating to your machine. Maker-stated guns compared.
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Picks that fit
- Kärcher Standard M22 Spray Gun 8.641‑024.0, up to 4,000 PSICheck price on Amazon
- SIMPSON 80148 universal pressure washer spray gun with side assist handle, 4,500 PSI, M22Check price on Amazon
- SIMPSON 80178 professional pressure washer spray gun, 5,075 PSI, hot and cold water, with M22 and QC adaptersCheck price on Amazon
Short answer
Match three things: the gun's inlet to your hose end, its outlet to your wand or nozzles, and its PSI, GPM and temperature rating to your machine. The rating must be at or above your machine's maximum. Keep a working trigger lock, and never use a gun whose lock is damaged or altered.
Picks that fitAll picks and how to choose
- Kärcher Standard M22 Spray Gun 8.641‑024.0, up to 4,000 PSICheck price on Amazon
- SIMPSON 80148 universal pressure washer spray gun with side assist handle, 4,500 PSI, M22Check price on Amazon
- SIMPSON 80178 professional pressure washer spray gun, 5,075 PSI, hot and cold water, with M22 and QC adaptersCheck price on Amazon
Three checks
- Inlet: the same standard, size and gender as your hose's gun end.
- Outlet: what your wand or nozzles need: M22, a pipe thread, a 1/4 in quick-connect or a brand bayonet.
- Rating: PSI and GPM at or above your machine's maximum, and a temperature rating for your water. Cat Pumps says a high-pressure system is only as strong as its weakest component.[2]
Pipe-thread guns
Some guns have tapered pipe-thread ports instead of M22:
- Suttner: lists most of its spray guns with a 3/8 in FPT inlet and a 1/4 in FPT outlet, each model with its own maximum PSI and GPM.[3] The ST-2000 is listed at 5,000 PSI and 10.4 GPM with those ports.[3]
- MTM Hydro SGS28: rated up to 4,000 PSI, 12 GPM and 320°F.[4] It has a 3/8 in FPT inlet with an integrated stainless steel live swivel and a 1/4 in FPT outlet.[4] MTM's listing names stainless steel only for the swivel; it states no body material.
A consumer M22 hose does not screw into a 3/8 in FPT port. It needs a fitting named for both ends; see the adapter guide.
M22 guns
- SIMPSON MSH3125 OEM gun: 3,650 PSI, 8 GPM, M22 male x M22 female (part 7109565).[5]
- Kärcher VersaGRIP and Standard M22: both have male M22 connections and are listed for washers rated up to 4,000 PSI.[6] The VersaGRIP has a Quick Connect inlet and ships with an M22 adapter needed only on M22 machines.[6] Kärcher says a nozzle cannot go directly on either gun; a wand goes on first.[6] Kärcher lists these consumer guns for cold-water machines only.[6]
- DEWALT DXPA45SG: rated up to 4,500 PSI, accepts M22 or quick-connect hose connections with an included QC adaptor, has an M22 wand outlet and a trigger safety lock-out.[7] DEWALT says cold water only.
Kits and short guns
- RYOBI RY31036K: a trigger handle kit with a metal wand and four quick-connect nozzles, listed for washers up to 3,600 PSI.[8] The page we read did not give the handle's inlet type.
- McKillans swivel gun: a maximum recommended 3,000 PSI and 2.6 GPM, with a 3/8 in male inlet and a 1/4 in female quick-connect outlet.[9] That outlet takes nozzles directly; see short gun vs gun and wand.
| Gun | Inlet | Outlet | PSI | GPM | Temperature |
|---|---|---|---|---|---|
| Suttner ST-2000 | 3/8 in FPT | 1/4 in FPT | 5,000 | 10.4 | Not stated |
| MTM Hydro SGS28 | 3/8 in FPT, live swivel | 1/4 in FPT | 4,000 | 12 | 320°F |
| SIMPSON 7109565 (MSH3125 OEM) | M22 male | M22 female | 3,650 | 8 | Not stated |
| Kärcher VersaGRIP / Standard M22 | Male M22 connections | Wand first | Up to 4,000 machine | Not stated | Cold-water machines |
| DEWALT DXPA45SG | M22 or QC (adaptor) | M22 | 4,500 | Not stated | Cold water only |
| McKillans swivel gun | 3/8 in male | 1/4 in female QC | 3,000 | 2.6 | Not stated |
Trigger force
Low trigger force guns need less finger effort to hold open. Suttner says its LTF guns such as the ST-2600 need 90% less holding force and 40% less trigger force than typical guns on the market.[10] That is Suttner's claim; we found no independent measurement. The ST-2600 itself is rated 310 bar (about 4,500 PSI) and 150°C, with a 3/8 in female inlet and a KW coupling outlet, per R+M Suttner's German shop.[10] That page gives two different flow figures, so we state none.
The trigger lock
A trigger lock holds the trigger closed when you stop spraying. DEWALT lists a trigger safety lock-out on the DXPA45SG,[7] and Kärcher a child safety lock on its bayonet gun.[11] Whatever gun you choose, use the lock every time you stop, and replace the gun if the lock is damaged.
Replacement guns
Picks that fit4 products
For an M22 hose on a machine rated 4,000 PSI or less, choose the Kärcher Standard M22 Spray Gun 8.641-024.0 (male M22 connections, cold-water machines; it needs a wand before the nozzle).
More on choosing
The SIMPSON 80148, 80147 and 80178 are SIMPSON replacement guns with different inlets and ratings: read the inlet, outlet, PSI and temperature on SIMPSON's page and pick the one whose inlet matches your hose and whose rating covers your machine. On Amazon, check that 'Ships from / Sold by' shows Amazon.com or the brand.
M22 gun with a stated pressure ceiling
SIMPSON gun with a side assist handle
SIMPSON 80148 universal pressure washer spray gun with side assist handle, 4,500 PSI, M22
SIMPSON standard replacement gun
SIMPSON 80147 universal pressure washer spray gun, 3,400 PSI, cold water, M22
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Questions
Are pressure washer guns universal?
No. Guns differ at the inlet (M22, quick-connect or 3/8 in FPT), at the outlet (M22, 1/4 in FPT, 1/4 in QC or a brand bayonet) and in rating. Kärcher, for example, lists its M22 guns only for machines rated 4,000 PSI or less.[6][3]
What size is a pressure washer gun inlet?
It depends on the gun. SIMPSON's MSH3125 OEM gun is M22 male x M22 female; Suttner's guns mostly have a 3/8 in FPT inlet; McKillans' swivel gun has a 3/8 in male inlet. Read your gun's own spec.[5][3][9]
Can I use a 4,000 PSI gun on a 4,400 PSI machine?
No. Every part must be rated at or above the machine's maximum, the same rule Generac's manual applies to hoses, and Cat Pumps says the system is only as strong as its weakest component.[12][2]
What is a low trigger force gun?
A gun designed to need less finger force to hold open. Suttner says its LTF guns such as the ST-2600 need 90% less holding force and 40% less trigger force than typical guns; that is Suttner's claim, not an independent measurement.[10]