In hydraulic and pneumatic systems, the piston and piston rod are subjected to continuous reciprocating motion under high pressure and varying loads. Without proper guidance and support, the metal surfaces of the piston and cylinder bore would come into direct contact, leading to friction, scoring, premature wear, and eventual system failure. Guide rings (also known as wear rings, support rings, or guide strips) are the essential components that prevent this metal-to-metal contact, providing reliable guidance, load absorption, and extended service life for hydraulic cylinders.Among the various materials used for guide rings, POM (Polyoxymethylene, also known as Acetal) has emerged as one of the most widely adopted engineering plastics for hydraulic and pneumatic guidance applications, offering an optimal balance of mechanical strength, wear resistance, dimensional stability, and cost-effectiveness.