Bearing Selection Guide

Choosing the right bearing starts with four questions: what load direction (radial, axial, or combined), what speed, what operating temperature, and what environment (dust, moisture, chemicals).

1. Load type

• Radial load only: deep groove ball bearings (6000/6200/6300 series) or cylindrical roller bearings (NU/NJ series).
• Axial load only: thrust ball bearings (51100/51200 series).
• Combined load: angular contact ball bearings (7200/7300 series) or tapered roller bearings (30200/30300 series).

2. Speed

Deep groove ball bearings handle the highest speeds. For very high-speed applications, consider precision-grade angular contact bearings (P5 or P4) with reduced clearance.

3. Temperature

Standard bearings operate up to 120degC. Above that, request high-temperature grease and C3 or C4 internal clearance to allow for thermal expansion.

4. Contamination

• Dusty or wet environments: sealed bearings (2RS) or shielded (ZZ).
• Very wet or washdown: stainless steel bearings with food-grade grease.
• Clean, oil-bath lubrication: open bearings.

5. Mounting

• Press-fit on shaft: cylindrical bore bearings.
• Tapered bore with adapter sleeve: easier mounting on long shafts.
• Pillow block units (UCP/UCF/UCT): bolt-on mounting, no shaft machining needed.

When in doubt, send the original bearing number to KIHOI for a direct cross-reference quote.