CAT 446-6021 BEARING

CAT 446-6021 is a Caterpillar genuine single-row deep groove ball bearing (open, unsealed, complete assembly including inner ring/outer ring/rollers/cage), suitable for the drive axle hubs and transmission output shafts of Cat 242D/252D skid steer loaders and 305.5E2 mini excavators. It is primarily designed to withstand radial loads, compatible with low axial loads, and suitable for low-to-medium speed, low-impact operating conditions, ensuring smooth operation of the wheel end/drivetrain. The following is complete professional information:

Core Technical Parameters (Professional Version)

Item Details
Basic Attributes
Model: 446-6021, Type: Single-row deep groove ball bearing (open, unsealed), Suitable for Cat 242D/252D skid steer loader drive axle hubs and 305.5E2 excavator transmission output shafts, Material: High carbon chromium bearing steel (GCr15, integrally hardened), Inner diameter: φ45 mm, Outer diameter: φ85 mm, Width: 19 mm, Weight: Approximately 0.48 kg, rated radial load 32 kN, axial load 8.5 kN, operating temperature -40℃ to +120℃, suitable shaft speed ≤4500 rpm, suitable bearing housing bore tolerance H7, radial clearance C3 grade (medium clearance, suitable for temperature difference conditions)

Key Dimensions: Inner diameter tolerance 0/-0.012 mm, outer diameter tolerance +0.015/-0.009 mm, width tolerance ±0.1 mm, raceway curvature radius 8.5 mm, chamfer at both ends 1.0×45°, coaxiality ≤0.02 mm, inner ring flange height 3.5 mm, outer ring flange height 3.0 mm, suitable journal diameter φ45 mm (tolerance f7), bearing housing bore inner diameter ≥85 mm, depth ≥19 mm

Material and Manufacturing Process: Inner ring/outer ring/roller are all GCr15 bearing steel (hardness HRC after quenching) 61-65), raceway surface hardened layer depth 1.8-2.2 mm, core hardness HRC 30-35, cage made of stamped low carbon steel (surface passivated for corrosion resistance), 13 rollers, roller diameter φ7 mm, cage pocket clearance 0.15-0.25 mm, corrosion resistance grade ISO 12944-5 (C3 level, suitable for humid conditions)

Compatible models: Cat 242D/252D skid steer loader drive axle wheel hub bearing, 305.5E2 mini excavator gearbox output shaft bearing. Often used with 205-4137 bearing outer ring and 8R-4145 sleeve sheath for radial support of wheel end/gearbox output shaft. Suitable for drive axle half-shaft speed ≤3800 rpm and gearbox output shaft torque ≤180 N・m.

Assembly fit: Outer ring and bearing housing bore interference fit (interference amount…) 0.008-0.012 mm), inner ring and shaft interference fit (interference 0.010-0.015 mm), rear end face runout ≤0.04 mm, radial runout ≤0.08 mm, uniform raceway contact marks, no edge contact.

Installation and Maintenance Points:

Before installation, clean the journal and bearing housing bore. Check the bearing for rust and raceway pitting/scratches. Use a dedicated pressure plate tool to press it in smoothly. Do not directly strike the inner/outer ring to prevent raceway deformation.

After installation, add Cat-specific extreme pressure grease (NLGI 2 grade, filling 2/3 of the bearing’s internal space). Replenish every 600 hours to avoid dry friction.

Maintenance Recommendations: Immediately stop the machine and inspect if the bearing operating temperature is >85℃ or abnormal noise occurs. Replace the bearing if raceway wear is >0.12 mm or roller surface peeling occurs. Regularly check the bearing housing seal to prevent dust/moisture ingress.