Bearing Selection Guide — Ball vs Roller vs Sleeve: How to Choose the Right Bearing

Choosing a Bearing

Wrong bearing choice is one of the most expensive design mistakes — it causes premature failure, excessive noise, heat, and downtime. This guide covers the major bearing types, when to use each, and the key selection criteria.

Bearing Type Comparison

Type	Radial Load	Axial Load	Speed	Precision	Cost	Maintenance
Deep Groove Ball	Good	Moderate	Very High	High	$	Low
Angular Contact Ball	Good	Good (one direction)	High	Very High	$$	Low
Cylindrical Roller	Excellent	None	High	High	$$	Low
Tapered Roller	Excellent	Excellent (one dir.)	Moderate	High	$$	Moderate
Spherical Roller	Excellent	Good	Moderate	Moderate	$$$	Moderate
Needle Roller	Good	None	High	Moderate	$	Low
Thrust Ball	None	Excellent	Moderate	High	$	Low
Plain / Sleeve	Good	None	Low-Moderate	Moderate	$	Varies
Linear Ball	Good (linear)	None	N/A (linear)	High	$$	Low

Decision Tree

Only radial load, high speed? → Deep groove ball bearing (the default choice)
Combined radial + axial load? → Angular contact (light axial) or tapered roller (heavy axial)
Heavy radial, no axial? → Cylindrical roller
Misalignment expected? → Spherical roller or self-aligning ball
Tight radial space? → Needle roller (very thin cross-section)
Pure axial/thrust load? → Thrust ball or thrust roller
Low speed, low cost? → Plain bearing (bronze bushing, oil-impregnated)
Linear motion? → Linear ball bearing or linear roller guide

Key Selection Criteria

L10 Life Calculation

Bearing life is rated in revolutions (or hours at a given RPM) using the basic dynamic load rating (C):

L₁₀ = (C / P)ᵖ × 10⁶ revolutions

C = basic dynamic load rating (from catalog)
P = equivalent dynamic load
p = 3 for ball bearings, 10/3 for roller bearings

L₁₀ hours = L₁₀ revolutions / (60 × RPM)

Speed Limits

Every bearing has a maximum speed rating. Beyond it, excessive heat generation causes premature failure. Use:

Grease lubrication: Lower speed limit (typically 70–80% of catalog max)
Oil lubrication: Higher speed limit
Oil mist/jet: Highest speeds (spindle bearings, turbines)

Fits and Mounting

See the Press Fit Chart for bearing shaft and housing fits. General rule:

Rotating inner ring → interference fit on shaft (j5/k5), clearance in housing (H7)
Rotating outer ring → clearance on shaft (g6), interference in housing (M7/N7)

When to Use Plain Bearings Instead

Very low speed (< 100 RPM) — rolling element bearings offer no advantage
Oscillating motion — rolling elements can brinell the raceway; bushings handle oscillation better
Dirty environments — sealed bushings are simpler and more contamination-tolerant
Cost-sensitive, high-volume — a bronze bushing costs pennies vs. dollars for a ball bearing
Space constraints — bushings can be thinner than rolling element bearings