CAT 320-8612 BUSHING

CAT 320-8612 is a Caterpillar steel retaining bushing, adapted for the hinge joints of pins in excavators, loaders, and other construction machinery. It supports the pins, reduces wear, and transmits loads. The following is raw data and does not include replacement parts information for Cat®…

Core Technical Parameters (Raw Data)

Item Details
Basic Attributes Model 320-8612, Type: Steel Fixed Bushing, Material: 42CrMo Alloy Steel, Single Weight: 2.85 kg, Operating Temperature: -40℃ to +150℃, Suitable Radial Load: ≤220 kN, Suitable Shaft Diameter: 80 mm, Fit Tolerance: H7, Corrosion Resistance: ≥144 hours Salt Spray, Surface Treatment: Quenching + Tempering + Blackening, Hardness: HRC 40-45, Tensile Strength: ≥1100 MPa, Yield Strength: ≥950 MPa, Fit Clearance: 0.015-0.030 mm

Key Dimensions (Metric/Imperial): Inner Diameter: 80 mm (3.150 in), Outer Diameter: 100 mm (3.937 in), Total Length: 75 mm (2.953 in), Wall Thickness: 10 mm, Chamfer: C2 mm, Flatness: ≤0.02 mm, Surface Roughness: Ra≤0.8 μm, Inner diameter tolerance +0.008/-0.00 mm, Outer diameter tolerance +0.012/-0.01 mm, Length tolerance +0.15/-0.05 mm, Roundness ≤0.015 mm

Performance Parameters: Impact toughness ≥65 J/cm², Elastic modulus 206 GPa, Poisson’s ratio 0.27, Coefficient of thermal expansion 12.5×10^-6/℃, Compressive strength ≥1850 MPa, Shear strength ≥630 MPa, Fatigue limit ≥530 MPa (10^7 cycles), Assembly interference 0.015-0.025 mm

Structure and Adaptability Characteristics: High-strength load-bearing structure: Integral forging of 42CrMo alloy steel, heat-treated with quenching and tempering, possessing high hardness, high toughness, and fatigue resistance, suitable for heavy loads and impact conditions, effectively preventing deformation and fracture, and ensuring pin positioning accuracy.

Fixed Support Function: The straight-tube, stepless structure allows for coaxial fixing of the pin and mounting base, reducing assembly deviations, improving component operational stability, and lowering the risk of abnormal wear due to inaccurate positioning.

Common Compatibility: Compatible with the boom pin, stick pin, bucket pin, and other hinged parts of Caterpillar 320D and 323D excavators and 950H loaders, suitable for frequent swinging and heavy-duty operations, and easy to install.

Compatible Models and Application Scenarios:

Excavators: Supports the boom hinge, stick connection, and bucket pin of models such as 320D, 323D, and 326D, ensuring stable operation of the working device and suitable for heavy-duty operations in mining, infrastructure, etc.

Loaders: Supports the boom hinge pin and rocker arm bushing of models such as 950H and 962H, suitable for frequent lifting and turning conditions during material loading and unloading, improving operational efficiency.

Other: Compatible with the working device pin positioning parts of some Caterpillar bulldozers and graders, meeting the high-strength positioning requirements under harsh working conditions.

Installation and Maintenance Points (Original Data)

Installation: Clean the bushing and mounting base, ensuring they are free of oil stains and metal shavings. Inspect the bushing for cracks, deformation, and surface damage.

Cold press installation (pressing force ≤180 kN). Do not hammer or strike. Ensure an interference fit (interference 0.015-0.025 mm). After installation, the coaxiality should be ≤0.02 mm.

After installation, check the inner diameter and roundness. Apply grease and run for 60 minutes, monitoring for abnormal heating and noise.

Maintenance: Check the bushing wear and positioning condition every 1000 hours. Replace immediately if wear exceeds 0.35 mm or positioning deviation exceeds 0.06 mm.

Regularly check the mounting base tightness. Use a dedicated pulling tool for disassembly to avoid prying, which could deform or damage the bushing.