CAT 172-1055 10mm Inner Diameter Flange Bushing

CAT 172-1055 is a straight, edgeless, steel-backed copper-based alloy bushing used by Caterpillar for connecting pins and joints in construction machinery. It is compatible with the boom, stick, or bucket pins of excavators and loaders. Its core function is to provide radial support, reduce wear, and cushion the impact. It can withstand heavy loads and frequent oscillations and is a key component for maintaining the flexible operation of the working device and extending the life of the pins and supports. It is suitable for medium and low speed, heavy-load oscillating conditions and has excellent wear resistance and impact resistance. The following is structured technical and application information:

Core Technical Parameters

Item Details
Basic Attributes
Model 172-1055, Type: Straight-type unscrewed bushing (steel-backed copper-based alloy), Material: Low-carbon steel back + high-strength brass (CuZn25Al5, hardness HB 110-130), Surface with axial lubrication grooves + radial oil holes (for grease flow), Single weight approximately 1.25 kg, Operating temperature: -25℃ to +150℃, Installation method: Cold-pressed interference fit (recommended interference 0.03-0.05 mm), Design life ≥8000 hours (normal operating conditions)

Key Dimensions
Inner diameter: 88.9 mm (3.5 inches, tolerance 0/+0.025 mm), Outer diameter: 101.6 mm (4 inches, tolerance 0/-0.02 mm), Total length: 101.6 mm (4 inches, tolerance 0/-0.12 mm), Lubrication grooves: 4 Strips (uniformly distributed, 2.5 mm wide, 0.8 mm deep), 2 radial oil holes (4 mm diameter, symmetrically distributed), inner hole surface roughness Ra≤0.8 μm, outer circle cylindricity≤0.015 mm, end face parallelism≤0.025 mm. Compatible Models and Parts: Compatible with Cat 320D, 323D, 326D excavators (boom-stick pin), 966K loader (bucket pin), M318F wheel excavator (boom cylinder pin), with matching 103-8329 elastic retaining ring, 5V-5498 retainer, 5P-0960 grease. Often installed in pairs with 172-1056 bushings.

Performance Parameters: Radial rated load ≥120 kN, allowable oscillation linear velocity ≤3 m/s, coefficient of friction ≤0.07 (grease lubrication), wear rate ≤0.008. mm/1000 hours, impact load resistance ≥30 kN, recommended lubrication cycle 500 hours (300 hours for heavy load conditions)

Structural and Performance Advantages: Steel-backed copper-based composite structure. The steel back ensures high strength and rigidity, while the copper-based alloy layer provides excellent friction reduction and anti-seize capabilities, suitable for heavy-load oscillation and boundary lubrication conditions. It prevents dry friction seizure between the pin and bushing, protecting the pin and support hole.

Axial lubrication groove + radial oil hole design efficiently stores and guides grease, forming a stable oil film, reducing friction loss, absorbing impact loads from the working device, reducing component fatigue, and improving the reliability of connection parts.

Straight structure without flanges adapts to various pin installations. Cold pressing installation is convenient. The steel back and copper layer are firmly bonded, eliminating the risk of delamination. It is suitable for frequent start-stop and variable load oscillation conditions, offering strong adaptability.

Installation and Maintenance Points: Before installation, clean the inner hole of the bushing, the pin, and the support hole, checking for burrs, rust, and dents. Measure the pin diameter (88.9 mm) and the inner diameter of the bushing, and the outer diameter of the support hole and the bushing, ensuring the interference fit meets requirements. Use a special press to evenly press the bushing into the support hole; do not strike the bushing end face to avoid deformation.

After installation, check the fit between the bushing end face and the support, ensuring no gaps or misalignment. After installing the pin, swing the joint to ensure no jamming. Add the recommended grease through the oil hole, ensuring the lubrication groove and oil hole are filled with grease.

Maintenance: Check the bushing wear and lubrication condition every 500 hours. If the copper layer peels off, the wear exceeds 0.15 mm, or the grease dries out, replace immediately. Replace bushings in pairs; do not repair the copper layer and reuse them to avoid abnormal wear of the pin and support.