CAT 523-0046 SLEEVE-SEM

CAT 523-0046 is a Caterpillar SEM (Surface Engineering Modification) wear-resistant sleeve used in hydraulic cylinder/connecting rod hinges. It is suitable for the boom/stick cylinder pins of Cat 320D/E and 336D/E excavators, enhancing the wear resistance and impact resistance of the pins and lugs. The following is raw data and does not include replacement parts information.

Core Technical Parameters (Raw Data)

Item Details
Basic Attributes
Model 523-0046, Type SEM Wear-resistant Sleeve (Seamless), Material Low Carbon Steel Matrix + Nickel-Chromium Alloy Coating, Single Weight 1.26 kg (2.778 lbs), Operating Temperature -40℃ to +120℃, Rated Radial Load ≥80 kN, Static Load Limit ≥200 kN, Permissible Maximum Sliding Speed ​​≤3 m/s, Lubrication Method Grease Lubrication (Compatible with Cat LBZ-2 Grease), Rated Life ≥8000 hours (Standard Operating Conditions)

Key Dimensions (Metric/Imperial)
Inner Diameter 76.20 mm (3.000 in), Outer Diameter 88.90 mm (3.500 in), Length 101.60 mm (4.000 in), Wall Thickness 6.35 mm, Chamfered Ends 2×45°, Inner Diameter Tolerance H7, Outer Diameter Tolerance h6, Length Tolerance ±0.10 mm, surface roughness Ra≤0.8 μm, coating thickness 0.15-0.25 mm
Matching and Performance Parameters: Fitting pin diameter 76.20 mm (f7 tolerance), fitting ear hole diameter 88.90 mm (H7 tolerance), radial clearance 0.04-0.08 mm, coefficient of friction ≤0.10 (grease lubrication), coating hardness HV 800-1000, substrate hardness HB 220-250, coefficient of thermal expansion 11×10⁻⁶/℃
Structure and Fitting Characteristics:
Structural Design: Seamless cylindrical structure, inner wall with SEM wear-resistant coating, outer wall with low-carbon steel substrate. It adapts to the transition fit between the hydraulic cylinder pin and the ear hole, isolating the pin from direct contact with the ear hole, reducing wear and frictional resistance, and extending the service life of the hinged parts.

Material and Process: The base material is made of low-carbon steel (Q235B), formed through rolling, welding, and heat treatment. The inner wall is coated with a plasma-sprayed nickel-chromium alloy coating, with a bonding strength between the coating and the base material ≥50 MPa. It possesses excellent wear resistance, corrosion resistance, and impact resistance, making it suitable for the harsh working conditions of construction machinery involving frequent start-stop cycles and heavy-load impacts.

Suitable Applications: Primarily used in the hinge pin areas of the boom cylinder, stick cylinder, and connecting rod of Cat 320D, 320E, 336D, and 336E excavators. It plays a crucial wear-resistant protective role in the relative movement of the pin and the lug, preventing premature wear of the pin and lug, and reducing maintenance frequency.

Installation and Maintenance Points (Original Data)

Installation: Clean the sleeve, pin, and ear hole surfaces, ensuring they are free of oil, metal shavings, and burrs. Use cold press-fitting with a pressing force ≤ 5 kN, ensuring an interference fit between the sleeve and ear hole (interference 0.02-0.04 mm). After installation, check the radial clearance and control it within 0.04-0.08 mm.

After installation, apply Cat LBZ-2 grease to ensure sufficient lubrication between the pin and the inner wall of the sleeve, preventing dry friction that could cause coating wear.

Maintenance: Check the sleeve for wear every 1000 hours. Replace immediately if the inner wall wear exceeds 0.10 mm or if the coating shows peeling or cracking.

Replenish grease regularly, adding it every 250 hours to ensure adequate lubrication of the hinged parts and prevent accelerated wear due to insufficient lubrication.