Plunger Bore: Diameter Tolerance ±0.005 mm, Roundness 0.003 mm

Component Specifications

Definition

A precisely machined cylindrical bore within a fluid chamber that serves as the guiding interface for a plunger's reciprocating motion. This critical component maintains dimensional accuracy and surface finish to ensure proper sealing, minimize friction, and enable efficient pressure generation or fluid displacement in hydraulic and pneumatic systems.

Working Principle

The plunger bore provides a smooth, dimensionally stable cylindrical pathway that guides the plunger's linear motion. As the plunger moves within the bore, it creates pressure differentials that displace fluid or generate force, with the bore's precision ensuring minimal clearance for effective sealing and efficient energy transfer.

Materials

Typically manufactured from hardened steel alloys (AISI 4140, 4340), stainless steel (316, 17-4PH), or specialized wear-resistant materials with hardness ranging from 45-60 HRC. Surface treatments may include nitriding, chrome plating, or DLC coatings for enhanced wear resistance.

Technical Parameters

Parameter	Typical range	Notes & selection driver
Length	Varies by application (typically 50-500 mm)
Roundness	0.003 mm
Straightness	0.01 mm/m
Surface Finish	Ra 0.2-0.4 μm
Diameter Tolerance	±0.005 mm
Operating Pressure	Up to 700 bar

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 3320, ISO 4394-1, DIN 24342, ISO 10766

Engineering Analysis

Risks & Mitigation

Wear and scoring from abrasive contaminants
Corrosion in aggressive fluid environments
Thermal expansion affecting clearances
Fatigue cracking under cyclic loading
Improper installation causing misalignment

FMEA Triads

Trigger: Contaminant particles in hydraulic fluid
Failure: Abrasive wear and scoring of bore surface
Mitigation: Implement proper filtration systems, regular fluid analysis, and use of wear-resistant coatings

Trigger: Improper alignment during assembly
Failure: Uneven wear, increased friction, and premature failure
Mitigation: Use precision alignment tools, follow installation procedures, and conduct post-installation verification

Trigger: Corrosive fluid media
Failure: Surface pitting and material degradation
Mitigation: Select corrosion-resistant materials, apply protective coatings, and implement fluid compatibility testing

Industrial Ecosystem

Compatible With

Typical Suppliers & Equivalents

Compliance & Inspection

Tolerance

ISO 286-1 geometric tolerancing standards for cylindrical features, with specific application-dependent clearances typically ranging from 0.01-0.05 mm

Test Method

Coordinate measuring machine (CMM) verification, surface profilometry, pressure testing per ISO 10766, and dimensional inspection per ISO 14253-1

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 Plunger Bore

Manufacturer profiles associated with Plunger Bore.

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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

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Main Frame

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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 plunger bore in industrial applications?

The plunger bore provides a precision-guided pathway for plunger movement, enabling controlled fluid displacement and pressure generation in hydraulic pumps, compressors, and fluid transfer systems.

How does surface finish affect plunger bore performance?

Optimal surface finish (typically Ra 0.2-0.4 μm) minimizes friction, reduces wear on both bore and plunger, improves sealing efficiency, and prevents fluid leakage in high-pressure applications.

What maintenance is required for plunger bores?

Regular inspection for wear, scoring, or corrosion; periodic cleaning to remove contaminants; and monitoring of dimensional tolerances to ensure continued performance and prevent system failures.

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.

Plunger Bore