The Caterpillar 3B-0645 Hex Nut is a high-tensile, heavy-duty mechanical locking fastener. It is engineered to maintain extreme clamping force and prevent joint relaxation across structural frame brackets, heavy mechanical linkages, and high-stress engine block attachments subject to relentless machine vibrations.
1. Core Dimensions & Fastener Specs
- Thread Size: 5/8 inch
- Hole Thread Pitch: 11 threads per inch (5/8-11 UNC Coarse Thread)
- Nut Thickness / Height: 13.89 mm (0.547 in)
- Drive / Hex Width Across Flats: 23.81 mm (15/16 in)
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Net Weight: 0.034 kg (0.076 lbs)
2. Material & Manufacturing Specs
- Material Grade: Premium high-strength hardened alloy steel (SAE J995 Grade 8 / Class 10 equivalent).
- Coating & Finish: Corrosion-resistant zinc plating or heavy-duty phosphate finish to prevent thread seizing, friction spikes, and environmental rust.
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Thread Hand: Standard Right-Hand (RH).
3. Equipment & System Compatibility
This coarse-threaded structural nut is standard heavy-duty hardware deployed across a vast selection of large-scale Caterpillar heavy machinery and high-horsepower engine platforms:
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Engine Platforms: Integrated into core structural components, exhaust manifolds, engine mounting brackets, and flywheel housing groups for CAT 3406, 3408, 3412, 3508, 3512, and 3516 engine series.
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Heavy Earthmovers & Track Dozers: Widely used within the chassis panels, suspension tracks, blade stabilizers, and ripper frame linkages of Caterpillar D8, D9, D10, and D11 fleets.
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Ultra-Class Mining Trucks: Deployed across body mount groupings, suspension cylinder clusters, and structural transmission mounts in CAT 777, 785, 789, 793, and 797 series mining haulers.
4. Part Cross-References
- Alternative Part Names: Coarse Thread Hex Nut, Heavy Hex Nut, Grade 8 Nut.
- Alternative Part Numbers: 3B0645, 3B-0645.
