TM NGRS CNC Piston with Steel Rack – 14.5 Teeth

RetroArms CNC Piston with 14.5-Tooth Steel Rack for Tokyo Marui NGRS
The body is not injection-molded but CNC-milled from a solid block of POM-C, allowing precise, straight geometry without sink marks and shape irregularities found in some injection-molded parts. POM-C offers high resistance to mechanical stress and wear, minimal moisture absorption, resistance to long-term exposure to oil, and a manufacturer-specified continuous operating temperature range from -60 °C to + 100 °C. The body features a solid bridge beneath the first pickup tooth to reinforce the stressed area, while the steel rack is guided in grooves to prevent it from lifting during operation. The rack itself is CNC-milled from 1.7102 spring steel and heat-treated to a hardness of 52–54 HRC. During production, the steel is annealed before machining to relieve internal stress, then milled, tumbled to remove sharp edges and finally heat-treated so that the finished rack is not unnecessarily brittle. The tooth geometry features the second tooth removed and the third tooth shortened by half, which according to the manufacturer helps protect the assembly during problematic cycling. Thanks to its combination of selected materials, precise machining and structural reinforcement, the piston is also designed for highly stressed NGRS builds.
Key Features

CNC-Milled POM-C Body
The body is machined from a solid block of POM-C, allowing precise, straight geometry without shape distortions associated with plastic injection molding.

1.7102 Spring Steel Rack
The CNC-milled rack made from 1.7102 spring steel undergoes controlled heat treatment and reaches a hardness of 52–54 HRC.

Reinforced Body Construction
A solid b..