Bearing Bore: Diameter tolerance H7 (ISO), Chamfer 0.5×45°

Component Specifications

Definition

A bearing bore is a precisely machined cylindrical cavity within an aluminum CNC machined bearing housing designed to accommodate and secure rolling element bearings (such as ball bearings or roller bearings). This component ensures accurate radial and axial positioning of the bearing, maintains proper clearance fits (typically H7 or similar tolerance grades), and provides structural support to handle operational loads while facilitating efficient heat dissipation and lubrication management in rotating machinery systems.

Working Principle

The bearing bore functions by providing a rigid, dimensionally stable interface that precisely locates the bearing outer race. It maintains interference or clearance fits as specified to prevent bearing creep under load while allowing for thermal expansion. The bore's surface finish and geometric accuracy (roundness, cylindricity) ensure even load distribution, minimize vibration, and extend bearing service life by reducing stress concentrations and misalignment.

Materials

Aluminum alloy (typically 6061-T6 or 7075-T6), with optional anodizing or hard coating for wear resistance. Material specifications include: density 2.7 g/cm³, tensile strength 310 MPa (6061-T6) or 572 MPa (7075-T6), thermal conductivity 167 W/m·K, and hardness 95 HB (6061-T6) or 150 HB (7075-T6).

Technical Parameters

Parameter	Typical range	Notes & selection driver
Chamfer	0.5×45°
Surface Finish	Ra 0.8-1.6 μm
Depth Tolerance	±0.05 mm
Diameter Tolerance	H7 (ISO)
Roundness Tolerance	0.005 mm
Cylindricity Tolerance	0.008 mm
Operating Temperature Range	-20°C to +150°C
Maximum Radial Load Capacity	Depends on housing design (typically 5-20 kN)

Ranges are indicative industry figures for RFQ preparation, not a supplier commitment. Confirm every value and standard with the legal manufacturer before ordering.

Standards

ISO 286-2, ISO 1101, DIN 7154, DIN 7182

Parent Products

This component is used in the following industrial products

Pivot Bearing Housing

A structural component that houses and supports the pivot bearing within a guiding roller assembly.

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Engineering Analysis

Risks & Mitigation

Bearing creep due to improper fit
Thermal expansion mismatch
Corrosion in harsh environments
Fatigue cracking under cyclic loads
Geometric inaccuracies causing premature bearing failure

FMEA Triads

Trigger: Insufficient interference fit or improper tolerance selection
Failure: Bearing outer race rotates within housing (bearing creep), leading to fretting corrosion, heat generation, and eventual catastrophic failure
Mitigation: Implement proper tolerance selection (H7 for clearance, P7 for interference), verify fit with go/no-go gauges, apply retaining compounds for critical applications

Trigger: Poor surface finish or geometric inaccuracies (out-of-round, taper)
Failure: Uneven load distribution on bearing, increased vibration, reduced bearing life, excessive heat generation
Mitigation: Implement strict quality control for surface finish (Ra ≤ 1.6 μm) and geometric tolerances (roundness ≤ 0.005 mm), use precision boring tools with proper tool maintenance

Trigger: Thermal expansion mismatch between aluminum housing and steel bearing
Failure: Fit changes during operation, leading to either excessive clearance or interference, causing bearing seizure or excessive play
Mitigation: Calculate thermal expansion coefficients for operating temperature range, design for worst-case scenarios, consider bearing materials with compatible expansion rates

Industrial Ecosystem

Compatible With

Typical Suppliers & Equivalents

Compliance & Inspection

Tolerance

H7 per ISO 286-2 for diameters up to 500 mm, geometric tolerances per ISO 1101

Test Method

CMM verification of diameter, roundness, and cylindricity; surface roughness testing per ISO 4287; functional testing with bearing installation and rotation under load

Procurement Evaluation Criteria

A practical evidence checklist for RFQ preparation and supplier evaluation.

Technical documentation

Request current drawings, revision history, and a signed specification sheet.

Manufacturing capability

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Inspection readiness

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Manufacturers of Bearing Bore

Manufacturer profiles associated with Bearing Bore.

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Frequently Asked Questions

What is the standard tolerance for bearing bores in aluminum housings?

The most common tolerance is H7 according to ISO 286-2, which provides a clearance fit for most bearing applications, typically ranging from +0.000 mm to +0.025 mm for a 50 mm bore.

Why is surface finish important for bearing bores?

Proper surface finish (typically Ra 0.8-1.6 μm) ensures even load distribution, prevents premature bearing wear, reduces friction heat generation, and maintains lubrication film integrity.

Can bearing bores be repaired if damaged?

Minor damage can be repaired using precision boring and sleeving techniques, but significant damage usually requires housing replacement to maintain dimensional accuracy and load capacity.

Data Basis

Editorial classification, named public sources where available, and source-reviewed manufacturer records. See the editorial policy.

Preliminary Technical Classification

This page supports structured research, RFQ preparation, and supplier evaluation. It does not replace buyer-led supplier qualification, standards review, or technical approval.

Bearing Bore