A Shock Absorber Piston is a key part of an automotive shock absorber and is responsible for generating the damping forces that control the motion of the vehicle's suspension during rough driving conditions. While the exterior of a shock absorber appears as a simple metal cylinder with two rings, the inner workings are much more complex and involve multiple components.
The Shock Absorber piston is typically constructed of aluminum or stainless steel and is a solid, round piece of metal. It is usually sand blasted and then coated with a polytetrafluorethylene (PTFE) coating, which provides the piston with a tough, long-lasting surface.
Shock absorbers are designed to damp vibrations of a vehicle's suspension caused by bumps and other road irregularities, which in turn reduces driver fatigue and prevents damage to the tires. This can also improve safety as it helps to prevent injuries.
To generate the damping forces needed to control the motion of the vehicle's suspension, a piston is connected to the inside of a tube filled with hydraulic fluid. When a bump or other road irregularity causes the piston to move, holes in the piston head permit the piston to pass through the fluid and absorb the forces that are produced.
In most shock absorbers, the piston is preloaded with a specific amount of pressure, which is controlled by a valve. This allows the shock to have a soft response to small bumps, and a stiffer, harder response to larger bumps or other more severe road irregularities.
During normal driving conditions, the piston moves within a zone defined by grooves in the pressure tube. This zone, called the "comfort zone", is designed to provide a smooth ride while reducing friction on the piston.
For more demanding driving, the piston moves out of the comfort zone and into a more restricted range of movement, called the "control zone". This zone allows the shock to damp lateral vibrations of the vehicle's suspension for increased control over the vehicle's handling.
The shock absorber piston is made of a special aluminum alloy, known as H-18 mm, which is lightweight and resistant to corrosion. It is also very flexible.
The piston rod is provided with an outside surface that is coated, at least partly, with a uniformly thick coating that comprises polytetrafluorethylene (PTFE), ceramic particles and a pigment that reduces friction and enhances wear resistance of the piston rod. The ceramic particles and the pigment comprise mullite and titanium oxide, respectively.
This coating is applied in a thin, uniform thickness ranging from 20 to 60 microns. The coating is sprayed in a spray booth and completely adhered to the rod, which can be made of sintered or steel.
The piston rod is then assembled to the body of the pressure tube using fasteners, such as bolts, which are tightened with the proper torque value so that the shock absorber won't lose its damping force during operation. The piston rod is also fitted with a rod guide, which gives the piston rod smooth movement and prevents the shock from moving backwards or forwards during compression or rebound.


Shock absorber piston is a device that absorbs impact when a vehicle collides with an object, and is used to disperse vehicle collision energy. The piston usually consists of two parts - the inner cylinder and the outer cylinder. The inner cylinder contains damping oil, and the outer cylinder contains nitrogen or excessive oil. The two parts are connected by a valve. The valve controls the damping force and allows the piston to work at different speeds under different conditions. The speed of the piston in the shock absorber plays an important role in its function. They shall operate at a speed of 1/4 to 2 feet per second. The piston must work properly within these limits, otherwise there is a risk of bottoming. If the piston touches the bottom, the shock absorber may fail. The piston of powder metallurgy shock absorber has high precision and high strength performance, which can be coated on the surface to make it decorative, corrosion resistant, wear-resistant and long life.