PLASTIC PISTON FOR DISC BRAKE

摘要

PURPOSE:To prevent damage of a square seal to roll back the piston or the internal walls of the cylinder by forming a hardened film of thermoplastics of no less than 1mum thick and thereby avoiding exposure of inorganic substance at the surfaces. CONSTITUTION:At the surface of a plastic piston 7 is formed a hardened layer 8 of no less than 1mum thick made of a thermoplastic resin as the matrix. Thereby the surface of piston is protected against corrosion by the brake liquid as well as the sealing material is prevented from damage, which assures well a much improved durability.