The 90 m / s FPS spring has been calibrated on 363 mm barrels and gearbox with type D cylinder (for pipes from 301 to 400 mm).
Of course with shorter or longer rods the performance will decrease or increase, so it will go to the harder or softer calibration.
In the calibration process the thickness due to the spring guide bearings and the piston head was not taken into consideration-
For this reason, given the same initial conditions, a performance increase of about 2.5 m / s must be taken into account for each bearing.
The FPS spring is 100% Made in Italy and was created in collaboration with leading companies in the sector.
The material used is burnished steel carbon pre-hardened steel with addition of silicon and chromium EN10270 / 2.
In the phase immediately following the forming, the spring is stabilized in the oven at a temperature of 400 degrees centigrade for thirty minutes in order to optimize its durability over time.
The spring has coils with variable pitch in the central area and in the area in contact with the spring guide and undergoes a grinding process at the two ends which ensures optimal performance during the compression phase.
The dimensions of the product are:
- length: 170 mm
- external diameter: 14.30 mm
It is recommended to use the spring in association with spring guides and piston bearing heads to ensure maximum performance and durability over time.

Warnings:

Use only original or certified compatible parts

Always verify compatibility with your specific model

Have installation performed by qualified or experienced personnel

Always wear safety goggles and cut‑resistant gloves

Do not modify or alter any components

Regularly inspect for wear and replace damaged parts immediately

Keep out of reach of children

Dispose of used parts according to local regulations