Brake Disc (Rotor): Thickness 20-40mm, Parallelism 0.01-0.02mm

Component Specifications

Definition

The brake disc, also known as a rotor, is a critical rotating component in disc brake systems that converts kinetic energy into thermal energy through friction. When hydraulic pressure activates the brake caliper, brake pads clamp onto both sides of the rotating disc, creating friction that decelerates the vehicle. Modern brake discs feature ventilation channels, slots, or drilled holes to dissipate heat and prevent brake fade during repeated or heavy braking applications.

Working Principle

The brake disc operates on the principle of friction-based energy conversion. As the disc rotates with the wheel, hydraulic pressure forces brake pads against both sides of the disc surface. The resulting friction converts the vehicle's kinetic energy into heat, which is dissipated through the disc's material and design features. Ventilated discs use internal vanes to create airflow, while slotted or drilled discs provide additional heat dissipation and gas evacuation paths.

Materials

Typically made from cast iron (gray iron or ductile iron) for standard applications, with high-carbon cast iron for performance vehicles. Some applications use composite materials (carbon-ceramic) for high-performance or racing vehicles, and coated discs (zinc, aluminum) for corrosion resistance.

Technical Parameters

Parameter	Typical range	Notes & selection driver
Weight	5-15kg depending on size
Diameter	200-400mm (passenger vehicles)
Hardness	180-240 HB (cast iron)
Thickness	20-40mm
Parallelism	0.01-0.02mm
Surface Finish	Ra 1.6-3.2μm
Runout Tolerance	0.05-0.10mm
Minimum Thickness	Specified by manufacturer (typically 1-2mm less than new)

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 15484, DIN 74281, SAE J431, JIS D 4311

Parent Products

This component is used in the following industrial products

Braking System

A safety-critical subsystem within the drive system that decelerates or stops a vehicle by converting kinetic energy into thermal energy through friction.

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Brake System

A safety-critical component that controls deceleration and stopping of a trolley.

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Engineering Analysis

Risks & Mitigation

Brake fade from overheating
Cracking under thermal stress
Corrosion in humid environments
Vibration/pulsation from uneven wear
Reduced braking efficiency with contamination

FMEA Triads

Trigger: Excessive heat generation during prolonged braking
Failure: Thermal cracking or warping
Mitigation: Use ventilated discs, proper material selection, and avoid prolonged heavy braking

Trigger: Corrosive environment exposure
Failure: Surface rust leading to uneven friction and vibration
Mitigation: Apply protective coatings, use corrosion-resistant materials, regular inspection

Trigger: Improper installation torque
Failure: Uneven contact leading to vibration and premature wear
Mitigation: Follow manufacturer torque specifications, use proper installation procedures

Industrial Ecosystem

Compatible With

Typical Suppliers & Equivalents

Compliance & Inspection

Tolerance

Diameter tolerance: ±0.5mm, Thickness variation: ≤0.015mm, Runout: ≤0.10mm

Test Method

Dimensional inspection per ISO 1101, Hardness testing per ISO 6506, Thermal cycling tests, Salt spray corrosion testing per ISO 9227

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.

Compare the published product scope and source details, then include your specifications and quantity in an enquiry.

Manufacturers of Brake Disc (Rotor)

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.

Shandong Sensitive Brake System Co., Ltd.

Dongying, Shandong, CN

Founded 2007

IATF16949 ISO14001 AMECA ECE R90 +1

Also makes: Brake Pad, Brake Shoe, Brake Lining and 3 more

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

Listed there as: “4. How many kinds of brake disc rotors?”
View source page ↗ sensitivebrake.com · recorded 2026-08-26

View profile Send enquiry

Explore company information and manufacturing capabilities, then discuss the scope of your project with a relevant supplier.

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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Brake Disc/Rotor

A rotating disc component in disc brake systems that converts kinetic energy into thermal energy through friction to slow or stop vehicle motion.

Frequently Asked Questions

What causes brake disc warping?

Brake disc warping typically results from uneven heat distribution during braking, improper torque application during installation, or material stress from rapid cooling (thermal shock).

How often should brake discs be replaced?

Replacement intervals vary by vehicle and driving conditions, but typically occur every 50,000-70,000 miles or when thickness reaches minimum specifications, cracks appear, or severe scoring/pulsation occurs.

What is the difference between solid and ventilated brake discs?

Solid discs are single-piece designs for lighter vehicles, while ventilated discs have internal vanes between two friction surfaces to improve heat dissipation for heavier vehicles or performance applications.

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.

Brake Disc (Rotor)