CAT 535-6331 85mm Inner Diameter Bushing

CAT 535-6331 SEM is a Caterpillar heavy-duty straight sleeve bushing, suitable for heavy-duty hinge points in excavators, loaders, and other equipment. It is used to withstand radial loads and low-speed oscillations, and is suitable for medium-to-high intensity impact conditions. The following is core technology and application information for Cat®…:

Core Technical Parameters

Item Details
Part Model: CAT 535-6331 (5356331) SEM Heavy-duty Straight Sleeve Bushing (Suitable for heavy-duty hinge points, matching pin 535-6330, compatible with NLGI 2 lithium-based grease)

Core Material: 20CrMnTi alloy carburized steel, surface carburized and quenched, hardness HRC 58–62, carburized layer depth 0.8–1.0 mm, inner hole with axial lubrication groove

Key Dimensions: Inner diameter 50.8 mm, outer diameter 63.5 mm, length 76.2 mm, wall thickness 6.35 mm, single weight approx. 1.2 kg (2.65 lb)

Rated Load: Rated radial load 120 kN, limiting speed 300 rpm, operating temperature -30℃ to +120℃

Compatible Models: CAT 320GC/323GC excavators (boom/stick hinge), 950M loaders (bucket/link hinge), 242D3 tracked loaders (rocker pin)

Suitable Working Conditions: Heavy load, continuous operation, swing frequency ≤3 times/minute, capable of withstanding medium to high intensity impact loads

Core Functions and Structural Features:

High Load Capacity: SEM heavy-duty quality, carburizing and quenching process, excellent impact resistance and wear resistance, service life of over 6000 hours under standard working conditions.

Efficient Lubrication: Internal axial lubrication groove design to store grease, reduce the coefficient of friction, and reduce adhesive wear between pins and bushings. Secure Installation: The direct-sleeve structure features an interference fit with the mounting hole (interference 0.02–0.04 mm). After installation, the coaxiality tolerance is ≤0.03 mm, ensuring transmission accuracy.

Installation and Maintenance Points

Installation Specifications: Clean the mounting hole and surface, ensuring it is free of oil and rust. Use cold pressing, controlling the pressing force at 20–25 kN. Do not strike the end face.

Mounting hole tolerance: +0.02–+0.04 mm. After installation, check for radial runout ≤0.03 mm.

After installation, apply NLGI 2 lithium-based grease, ensuring the lubrication groove is full.

Maintenance Recommendations: Check the operating status every 600 working hours, looking for abnormal noises, abnormal temperature rise, and seal leaks.

Replace the device promptly when the inner diameter wear exceeds 0.15 mm. Replace the device simultaneously with the matching pin and sealing ring to ensure sealing and lubrication effectiveness.