CAT 421-5646 110mm Inner Diameter Guide Ring

CAT 421-5646 is a Caterpillar genuine piston guide support ring, suitable for guiding and positioning pistons in hydraulic pumps/motors, used in high-pressure hydraulic systems of excavators, loaders, and other equipment. The following are precise original factory specifications and application information; replacement parts are not included.

Core Technical Parameters

Item Details
Part Model CAT 421-5646 (Piston Guide Ring, for Hydraulic Pumps/Motors)

Product Type: Hydraulic components for engineering machinery, compatible with axial piston pumps/motor pistons, providing guidance, positioning, and anti-wear functions, and bearing radial loads and reciprocating friction.

Material: Base material: Glass fiber reinforced nylon (PA66+30% GF), surface-added solid lubricant (PTFE+MoS₂), coefficient of friction μ≤0.1

Key Dimensions: Inner diameter 60 mm (2.362 in), outer diameter 75 mm (2.953 in), width 12 mm (0.472 in), chamfer 0.5 mm, radial clearance 0.05–0.10 mm

Rated Parameters: Applicable working pressure ≤ 35 MPa, applicable temperature -40℃ ~ +120℃, applicable reciprocating speed ≤ 1.8 m/s

Physical Properties: Density 1.38 g/cm³, hardness Shore D 85, Tensile strength 180 MPa, Coefficient of thermal expansion 3.5×10⁻⁵ /℃
Single weight: Approx. 0.11 kg (0.24 lbs)
Compatible media: Mineral oil, synthetic hydraulic oil, phosphate ester hydraulic oil, etc.
Structure and core characteristics:
Low friction and high wear resistance: Reinforced nylon substrate + solid lubricant, suitable for high-pressure reciprocating conditions, reducing direct contact between piston and cylinder, reducing wear and energy loss.

Precise guidance and positioning: Strictly controlled radial clearance prevents piston wobble during reciprocation, ensuring the stability of hydraulic pump/motor flow and extending seal life.

Impact resistance and media resistance: Glass fiber reinforced structure, can withstand hydraulic impact loads, good chemical stability, suitable for various hydraulic oil media, and not prone to aging and deformation.

Self-lubricating design: No additional lubrication required, reducing maintenance costs, suitable for long-term continuous operation.

Compatible Models and Application Scenarios

Compatible Equipment: CAT 320D2/323/336 excavators, 950M/966M loaders, some C-series axial piston pumps (such as the 146-0817 pump set), and swing motors (such as the 246-6318 motor).

Core Purpose: Installed in the piston guide groove of the axial piston pump/motor, it provides radial support and guidance, prevents piston wear on the cylinder body, and is suitable for high-pressure, high-frequency reciprocating hydraulic conditions, ensuring pump/motor output efficiency and reliability.