SA Polycarbonate Piston with 14 CNC Steel Teeth – Blue

Specna Arms polycarbonate piston with 14 CNC-machined steel teeth

The piston body is made from durable polycarbonate, while the stressed section consists of a complete steel rack with 14 teeth. CNC-machined steel teeth offer the highest mechanical durability and are suitable for long-term use in both standard and higher-performance builds. In standard configurations, for example with an M120-M130 spring, the CNC-machined rack provides a more durable solution than pistons with alloy teeth. An important design feature is the removed second piston tooth. This design provides more room for correct sector gear engagement and makes AOE (Angle of Engagement) adjustment easier, as common modifications do not require the second tooth to be additionally shortened or ground down as with some 15-tooth pistons. At the same time, in a correctly assembled gearbox, it can help reduce the risk of premature piston engagement at high RoF. The piston is designed primarily for V2 / V3 AEG platforms and others using a standard-length piston, such as V6 / V7 or M249, and is suitable not only for Specna Arms guns.

Key features of the Specna Arms piston with 14 CNC-machined steel teeth

Technical specifications

• Manufacturer: Specna Arms
• Series: Upgrade Parts
• Type: Piston for AEG gearbox
• Body material: Polycarbonate
• Teeth material: Steel (CNC-machined)
• Number of steel teeth: 14
• Design: Full steel rack
• Second tooth: Removed
• Body colour: Blue
• Designed for: AEG

Package contents

• 1× Specna Arms polycarbonate piston with 14 CNC-machined steel teeth

Frequently asked questions from our store

Why does the piston have only 14 steel teeth?

The piston intentionally has the second tooth removed. This design provides room for correct sector gear engagement and makes AOE adjustment easier. On 15-tooth pistons, the second tooth often needs to be shortened or removed when tuning the gearbox.

What does AOE mean on a piston?

AOE (Angle of Engagement) refers to the angle and position at which the first tooth of the sector gear engages the piston. Correct adjustment helps distribute stress on the first tooth and is particularly important in upgraded or faster-cycling gearboxes.

Are CNC-machined teeth more durable than conventional metal teeth?

Yes, the CNC-machined steel rack itself offers significantly higher resistance to wear and stripping than alloy teeth. However, the service life of the entire piston still depends on correct gearbox assembly, AOE, spring power, gear ratio, RoF and other drivetrain components.

Will this piston help at high RoF?

The design with the second tooth removed is suitable for AOE tuning and faster builds, but by itself it does not guarantee trouble-free operation at high RoF. In high-speed builds, the gears, motor, spring, timing and piston movement must be properly matched to prevent premature engagement of the piston by the sector gear.