Description
ACM Piston with 1 Steel Tooth with Piston Head
This is an ACM replacement piston for airsoft electric guns (AEGs), with one steel tooth and supplied with a piston head. The piston is one of the hardest-working parts in an AEG gearbox, and a worn or broken piston is one of the most common reasons for a gun to stop firing properly.
ACM makes a wide range of affordable airsoft parts and accessories. This piston is a low-cost replacement for players and technicians servicing an AEG, or for anyone who wants a spare piston on the workbench.
What the piston does
Inside the gearbox, the sector gear catches the teeth on the underside of the piston and pulls it back, compressing the main spring. When the last tooth is released, the spring drives the piston forward and the piston head pushes air through the cylinder head and nozzle to fire the BB. This happens every shot, so the teeth take a lot of stress.
Why one steel tooth
The tooth that takes the most wear is usually the last one before release, as it carries the full load of the compressed spring. A steel tooth at that point is harder-wearing than one made from plastic, which helps the piston last longer. Check the product images to see which tooth is steel on this piston.
Key features
- Replacement AEG piston
- One steel tooth for added wear resistance
- Piston head included, as listed
- Affordable spare for repairs and servicing
- From ACM
What’s in the box
- Piston
- Piston head (as listed)
Compatibility
Gearbox versions and spring strengths vary, so confirm the piston suits your gearbox before ordering. When fitting a new piston, check the angle of engagement (AOE) between the sector gear and the piston, and make sure the piston head seals well in your cylinder. If you are not confident working on gearboxes, have the part fitted by a technician.
Care and maintenance
Apply a light coat of suitable gearbox grease to the piston teeth and rails when fitting. During servicing, check the teeth for chipping or wear and the piston head O-ring for damage. A piston that keeps stripping usually points to another problem, such as poor AOE or a spring that is too strong, so look at the whole gearbox.
Who is it for?
For players and technicians repairing or servicing an AEG gearbox who want an affordable replacement piston.
Please note: Fitting requires the gearbox to be opened. Only work on your replica with the battery removed.
