How is the relubrication interval calculated?

The SKF method uses: tf = K × (14×10⁶/(n×√dm) − 4×dm) hours as a base, then adjusts for bearing type, temperature, contamination, and orientation. K depends on bearing type (1.0 for DGBB, 0.5–0.8 for roller bearings).

What factors reduce the relubrication interval?

High temperature (halve for each 15°C above 70°C), heavy contamination (0.5–0.1×), vertical shaft (0.5×), vibration/shock loads (0.5–0.75×), and high humidity (0.5×) all reduce the interval.

What is a typical relubrication interval?

For standard electric motors at 1500 RPM with DGBB, typical intervals are 10,000–20,000 hours. For high-speed applications, it can be as low as 500–2,000 hours. Very slow or sealed bearings may last 30,000+ hours.

Does the SKF method apply to all grease types?

The base SKF formula assumes standard lithium/lithium-complex grease. For synthetic or polyurea greases, the interval can be multiplied by 2–4. For calcium-based greases, reduce by 0.5.

Should I regrease sealed bearings?

Factory-sealed bearings (2RS, ZZ) are typically 'lubricated for life' and should not be regreased. Their grease life depends on temperature and speed. Replace the bearing when grease is depleted.

Free Engineering Tool #052

Bearing Relubrication Interval Calculator

Calculate grease relubrication interval using the SKF-style method. Adjustments for temperature, contamination, bearing type, and orientation.

SKF MethodTemperature Adj.Contamination Adj.

Results

Adjusted Relubrication Interval

—

Base Interval (before adjustments)

—

Temperature Factor

—

Mean Diameter dm

—

Base Relubrication Interval (SKF)

K — bearing type factor
n — speed (RPM)
d_m — mean bearing diameter (mm)

Adjustment Factors

The base interval is multiplied by adjustment factors:

Factor	Condition	Multiplier
f_T (Temperature)	≤70°C	1.0
	85°C	0.5
	100°C	0.25
	120°C	0.1
f_C (Contamination)	Clean	1.0
	Moderate dust	0.7
	Heavy	0.4
	Severe	0.2

⚠️ Note: This is a simplified estimation. For precise intervals, use the bearing manufacturer’s software (SKF Bearing Calculator, Schaeffler medias, etc.).

Bearing Relubrication Interval Calculator | SKF Method | Free Online Tool

Published by admin on February 15, 2026 February 15, 2026

Results

Base Relubrication Interval (SKF)

Adjustment Factors