Bleeder Screw: Length 15-25mm typical

Component Specifications

Definition

A specialized threaded fastener designed for brake calipers that provides a controlled opening to purge trapped air from hydraulic brake lines during bleeding procedures. It features a tapered sealing surface and precise thread geometry to maintain system integrity while allowing fluid flow when opened.

Working Principle

The bleeder screw operates on a simple valve principle: when tightened, its tapered tip creates a metal-to-metal seal against the caliper body, preventing fluid leakage. When loosened, it creates a small passage that allows air bubbles to escape while brake fluid flows through, following the principle of hydraulic pressure equalization.

Materials

Typically made from corrosion-resistant steel alloys (such as SAE 1018 or 1045 carbon steel with zinc plating, or stainless steel 304/316), brass, or aluminum alloys. High-performance versions may use titanium or specialized coatings for extreme conditions.

Technical Parameters

Parameter	Typical range	Notes & selection driver
Length	15-25mm typical
Head Type	Hex socket (Allen), external hex, or slotted
Thread Size	M7x1.0, M8x1.0, M10x1.0, or 3/8-24 UNF
Sealing Method	Tapered seat (conical) or crush washer
Pressure Rating	Withstands up to 2000 psi (138 bar)
Torque Specification	8-15 Nm (6-11 ft-lbs)

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 4032, DIN 934, SAE J429, ISO 898-1

Parent Products

This component is used in the following industrial products

Brake Caliper

A hydraulic or mechanical device that applies clamping force to brake pads against a rotor to slow or stop a vehicle.

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Engineering Analysis

Risks & Mitigation

Thread stripping during installation
Corrosion leading to seizure
Improper sealing causing brake fluid leaks
Shearing during removal if corroded

FMEA Triads

Trigger: Corrosion due to exposure to moisture and road salts
Failure: Screw seizes in caliper, preventing brake bleeding
Mitigation: Use corrosion-resistant materials, apply anti-seize compound, implement regular maintenance schedules

Trigger: Over-torquing during installation
Failure: Thread damage or screw shearing
Mitigation: Use calibrated torque wrenches, follow manufacturer specifications, train technicians properly

Trigger: Worn sealing surfaces
Failure: Brake fluid leakage leading to reduced braking performance
Mitigation: Replace screws during brake service, inspect sealing surfaces, use proper replacement parts

Industrial Ecosystem

Compatible With

Typical Suppliers & Equivalents

Compliance & Inspection

Tolerance

Thread tolerance: 6g per ISO 965-1, dimensional tolerance: ±0.1mm

Test Method

Pressure testing per SAE J1703, corrosion resistance per ASTM B117 salt spray test, torque-to-failure testing

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 Bleeder Screw

Manufacturer profiles associated with Bleeder Screw.

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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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Frequently Asked Questions

What happens if a bleeder screw is overtightened?

Overtightening can strip threads in the caliper body, damage the tapered sealing surface, or cause the screw to shear off, requiring caliper replacement.

Can bleeder screws be reused?

While technically reusable, replacement is recommended during brake service as the sealing surfaces degrade over time, increasing risk of fluid leaks.

Why do some bleeder screws have different thread sizes?

Thread sizes vary by vehicle manufacturer, caliper design, and brake system pressure requirements to ensure proper sealing and compatibility.

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.

Bleeder Screw