Cooling Holes: Diameter 1.5-5 mm, Positional Tolerance ±0.1 mm

Component Specifications

Definition

Cooling holes are critical components in internal combustion engine liners, typically cylindrical or shaped apertures strategically positioned to allow controlled passage of coolant (usually water or ethylene glycol mixture) from the cooling jacket into the liner wall. They function as part of the engine's thermal management system, dissipating heat generated during combustion to maintain optimal operating temperatures, reduce thermal expansion, and prevent material degradation. Their design involves precise diameter, spacing, and angle calculations to ensure uniform cooling without compromising structural integrity.

Working Principle

Cooling holes operate on the principle of convective heat transfer. During engine operation, high temperatures from combustion heat the liner. Coolant is pumped through the engine's cooling system and flows through these holes, absorbing heat from the liner walls. The heated coolant then circulates to the radiator, where it dissipates heat to the environment before returning. This continuous cycle maintains the liner at a stable temperature, preventing hotspots and ensuring efficient engine performance.

Materials

Typically made from cast iron (e.g., gray cast iron, ductile iron) or aluminum alloys for lightweight applications. Material must have high thermal conductivity, corrosion resistance, and mechanical strength. Common specifications include ASTM A48 for cast iron or SAE 300 series aluminum alloys, with surface treatments like nitriding or chrome plating to enhance durability.

Technical Parameters

Parameter	Typical range	Notes & selection driver
Depth	Full wall thickness of liner (typically 5-15 mm)
Taper	0-5 degrees for ease of manufacturing
Spacing	10-30 mm between holes
Diameter	1.5-5 mm
Surface Finish	Ra ≤ 3.2 μm to prevent crack initiation
Positional Tolerance	±0.1 mm

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, DIN 7154, SAE J429

Parent Products

This component is used in the following industrial products

Liner

A protective inner wall component of a gas turbine combustion chamber that contains and directs the combustion process.

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Engineering Analysis

Risks & Mitigation

Clogging from coolant contamination
Corrosion due to improper coolant pH
Cracking from thermal fatigue
Improper alignment causing uneven cooling

FMEA Triads

Trigger: Contaminants in coolant (e.g., debris, scale)
Failure: Reduced coolant flow, overheating, engine seizure
Mitigation: Implement regular coolant filtration, use high-quality coolants, schedule preventive maintenance

Trigger: Material fatigue from thermal cycling
Failure: Crack formation in holes, coolant leakage, loss of pressure
Mitigation: Design with fatigue-resistant materials, apply surface treatments, monitor operating temperatures

Trigger: Manufacturing defects (e.g., incorrect hole size or placement)
Failure: Inefficient cooling, hotspots, increased wear
Mitigation: Adhere to strict quality control (e.g., ISO 9001), use precision machining, conduct post-production inspections

Industrial Ecosystem

Compatible With

Internal combustion engines, diesel engines, industrial machinery with cooling systems

Typical Suppliers & Equivalents

Caterpillar, Cummins, Bosch, Perkins, Yanmar

Compliance & Inspection

Tolerance

Hole diameter tolerance: ±0.05 mm; Positional tolerance: ±0.1 mm as per ISO 286-2

Test Method

Pressure testing (e.g., up to 3 bar for leakage), flow rate measurement, thermal imaging for heat distribution, dimensional inspection using CMM

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 Cooling Holes

1 company lists this product among what they make. Company figures are quoted from each company's own website; every card states where the relationship came from.

LaserMicroFab

Shenzhen, Guangdong, CN

Also makes: Aerospace Components, Nozzle Plate, SMT Stencil and 7 more

Listed on the company's own website · profile compiled by CNFX from public sources

Listed there as: “turbine cooling holes”
View source page ↗ lasermicrofab.com · checked 2026-09-14

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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

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Frequently Asked Questions

What happens if cooling holes become clogged?

Clogged cooling holes restrict coolant flow, leading to localized overheating, thermal stress, potential liner cracking, and reduced engine efficiency. Regular maintenance and coolant filtration are essential.

Can cooling holes be repaired if damaged?

Minor damage can sometimes be repaired by reaming or welding, but severe damage often requires liner replacement to maintain structural integrity and cooling performance.

How are cooling holes manufactured?

They are typically drilled using CNC machines, EDM (Electrical Discharge Machining), or laser drilling for precision, followed by deburring and surface finishing to meet specifications.

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.

Cooling Holes