---
title: "how to choose bearing size"
date: 2026-07-17
description: "Choosing the correct ball bearing depends on load type, speed, temperature, and application environment. Mismatched bearings cause 30% more machinery downtime, ..."
source: https://en.mshjzc.com/blog/56139.html
---

# how to choose bearing size

Choosing the correct ball bearing depends on load type, speed, temperature, and application environment. Mismatched bearings cause 30% more machinery downtime, per MS Bearings’ technical data. This guide outlines clear steps to pick bearings that extend equipment lifespan and reduce maintenance costs.

## Load & Speed Requirements

Two core load types define bearing selection: **radial load** (perpendicular to the shaft) and **axial load** (parallel to the shaft). For light to moderate radial loads at high speeds, deep groove ball bearings (series 6000, 6200, 6300) work best. A 6205 deep groove bearing handles up to 5000 rpm under 1000N radial load, ideal for conveyor systems. Angular contact ball bearings suit high axial loads, with a 7205 model supporting up to 2000N axial load at 8000 rpm, used in pump shafts and gearboxes.

## Operating Temperature & Environment

Temperature extremes and contamination risk dictate bearing material and sealing. Standard steel bearings fail above 120°C; switch to ceramic ball bearings (Si3N4) for 180°C continuous operation, common in furnace conveyors. For corrosive environments (food processing, chemical plants), 316 stainless steel bearings (series S6200) resist acids and moisture, with IP67-rated 2RS seals to prevent debris entry. MS Bearings maintains a 95% stock of corrosion-resistant bearings for industrial use.

## Precision & Tolerance Levels

Precision class affects machinery accuracy. Standard P0 grade bearings suit general equipment like fans or conveyors. For high-precision applications (CNC machines, robotic arms), choose P6 or P4 grade bearings, which have tighter dimensional tolerances (±0.005mm vs ±0.01mm for P0). A P4 grade 6205 bearing ensures minimal runout, critical for 0.01mm precision machining.

## Installation & Maintenance Compatibility

Bearing installation ease reduces downtime. Double-sealed (2RS) bearings require no external lubrication for 20,000 hours, while shielded (ZZ) bearings work for dusty environments. Ensure shaft and housing tolerances match the bearing’s dimensions: a 6205 bearing has a 25mm inner diameter, so the shaft must have a h6 tolerance (±0.005mm) for proper fit. For project-specific requirements, consult your bearing supplier. Contact MS Bearings for free technical support.

What is the maximum rpm for a standard deep groove ball bearing?

A standard 6205 series deep groove ball bearing can operate at up to 12,000 rpm under light radial load conditions (≤500N).

Which bearing type is best for high axial loads?

Angular contact ball bearings are ideal for high axial loads, with load capacity up to 2 times that of deep groove bearings at the same outer diameter and width.