As opposed to most other types of springs, gas spring mounting bracket use a integrated pretension force and a flat spring characteristic. Which means there's merely a small improvement in force between full extension and full compression.
As the piston and piston rod are pressed into the cylinder, volume reduces and pressure increases. This causes pushing force to improve. In conventional gas-type springs, this increase is usually around 30% at full compression.
The pushing spring movement is slow and controlled. It is just a few the gas flow between your piston sides being allowed to pass through channels in the piston throughout the stroke. Conventional gas springs use 'hydraulic damping', involving a modest amount of oil slowing down the rate from the stroke immediately prior to the spring reaches full extension. This provides the movement a braking character at the conclusion position provided the piston rod is incorporated in the downward direction.
Force tolerances when charging with gas along with other factors mean that there might be variations inside the force exerted by gas springs with similar nominal value.
The nominal values apply at 20° C, which is the temperature where gas charging is carried out. Note that when the ambient temperature rises or falls, the force from the spring rises or falls based on pressure modifications in the cylinder. Usually of thumb, gas spring force increases by approximately 3.5% per 10° C temperature increase and reduces accordingly once the temperature falls.