AA PIANO Wire Steel Spring for AEG - M140

AEG PIANO Spring with Progressive Coil by Action Army

The spring is a key component of the gearbox because its strength, together with air seal quality, directly affects the overall performance of the gun. Low-quality springs may initially offer higher-than-rated performance but tend to lose tension quickly, shorten, or even break—especially if stored compressed or left in pre-cocked mode.
The PIANO upgrade spring from Action Army is engineered for maximum performance consistency and long service life. Crafted from high-grade spring steel, it resists wear even during high-rate-of-fire scenarios.
Its progressive coil starts off soft and becomes stiffer, easing the load on the gear mechanism and motor. Each spring is pre-tensioned at the factory, ensuring stable performance from the first cycles—unlike cheaper alternatives.

Installation

When installing a spring with progressive winding, the compressed end (the section with tighter coils) goes onto the spring guide.

Available Action Army AEG Spring Strengths

• M95 (1 Joule)
• M100
• M120
• M130
• M140
• M150

Technical Specifications

• Stiffness: M140
• Output after installation: Approx. 140 m/s
• Material: Spring steel
• Winding: Progressive
• Compatibility: Most AEG gearboxes (excluding V2.5, L85, PSG-1, and other atypical versions)

Package Contents

• AEG PIANO Spring