Mounting Bore: Diameter Tolerance H7 or tighter

Component Specifications

Definition

A mounting bore is a critical cylindrical feature machined into a precision forged gear blank, typically serving as the primary interface for attaching the gear to a shaft or hub. It ensures proper concentricity, torque transmission, and axial positioning within mechanical power transmission systems. The bore's dimensions, surface finish, and geometric tolerances are precisely controlled to maintain alignment with gear teeth and prevent operational issues like vibration or premature wear.

Working Principle

The mounting bore functions by providing a precise interference or clearance fit with a mating shaft, secured via mechanical fasteners (e.g., keys, splines, or set screws). It transfers rotational forces from the gear teeth to the shaft while maintaining radial and axial alignment through controlled tolerances and surface contact. In operation, it ensures minimal runout and balanced load distribution across the gear-shaft interface.

Materials

Typically matches the gear blank material: alloy steels (e.g., AISI 4140, 4340), carbon steels, or specialty alloys. Hardness ranges from 28-45 HRC post-heat treatment. Surface treatments may include nitriding or carburizing for wear resistance.

Technical Parameters

Parameter	Typical range	Notes & selection driver
Depth	As per gear width specifications
Roundness	≤ 0.01 mm
Concentricity	≤ 0.02 mm relative to pitch diameter
Surface Finish	Ra 1.6 μm or better
Diameter Tolerance	H7 or tighter

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, DIN 7154, ISO 1101

Engineering Analysis

Risks & Mitigation

Misalignment causing gear wear
Inadequate fit leading to slippage
Surface defects inducing stress concentrations

FMEA Triads

Trigger: Improper machining tolerances
Failure: Shaft misalignment and excessive vibration
Mitigation: Implement statistical process control (SPC) and regular gauge calibration

Trigger: Material fatigue or corrosion
Failure: Bore deformation or cracking under load
Mitigation: Use corrosion-resistant materials and apply protective coatings

Industrial Ecosystem

Compatible With

Typical Suppliers & Equivalents

Compliance & Inspection

Tolerance

ISO 286 for dimensional tolerances, ISO 1101 for geometric tolerances

Test Method

Coordinate measuring machines (CMM), bore gauges, surface profilometers

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

Verify equipment lists, process limits, capacity, and representative production evidence.

Inspection readiness

Confirm test methods, calibrated equipment, sampling plans, and traceable reports.

Supplier transparency

Check the legal entity, factory address, ownership, certifications, and direct contacts.

CNFX does not score or rank suppliers. Buyers must verify all claims and documents with the legal manufacturer before ordering.

Manufacturers of Mounting Bore

Manufacturer profiles associated with Mounting Bore.

Sourcing Mounting Bore from China?

Tell us your specification and target quantity — we will match it against manufacturer records and come back with the factories that fit.

Request manufacturers We manufacture this

Manufacturer listings support early research and capability understanding. They are not certification, ranking, or transaction guarantees.

Compiled and source-reviewed by the CNFX editorial team. Each manufacturer above links to the page on that company's own website where the product is listed, with the date we checked it. How we source and review

Related Components

Upper Tool (Punch)

Upper Tool (Punch) is the active forming component in metal plate bending machines that applies precise downward force to create bends in sheet metal.

Main Frame

The main frame is the primary structural component of a hydraulic press, providing rigidity and stability to withstand high compressive forces during metal forming operations.

Shaft Bearing

Precision component supporting rotating shafts in vibration motors to reduce friction and maintain alignment.

Seal Groove

Precision-machined groove in aluminum bearing housings designed to accommodate sealing elements for fluid containment and contamination prevention.

Frequently Asked Questions

What is the primary function of a mounting bore in a gear blank?

It provides a precise interface for attaching the gear to a shaft, ensuring accurate alignment, torque transmission, and minimal vibration in mechanical systems.

How are mounting bores typically secured to shafts?

Common methods include keyways, splines, tapered fits, or set screws, chosen based on torque requirements and assembly/disassembly needs.

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.

Mounting Bore