Brake Pad Parts: The Components That Stop Your Car

A brake pad typically consists of a friction material (lining), a steel backing plate, a noise-dampening shim, an underlayer or cushion, bonding/mechanical retention features, chamfers and slots in the lining, and a wear indicator (mechanical tab or electronic sensor). Together, these parts convert kinetic energy into heat, manage noise and vibration, and ensure the pad stays securely attached and wears predictably.

The essentials: What every modern disc-brake pad is made of

While designs vary by vehicle and manufacturer, most automotive disc-brake pads share a common set of core parts. These components work in concert to deliver stopping power, control heat, reduce noise and vibration, and maintain structural integrity under extreme loads.

• Friction material (lining): The working face of the pad that contacts the rotor. Compounds include ceramic, semi-metallic, and NAO/organic blends with fibers, fillers, abrasives, lubricants (e.g., graphite), and binders. Most new pads are “copper-free” to meet 2025 U.S. regulations limiting copper to under 0.5% by weight.
• Backing plate: A precision-stamped steel plate that supports the lining and interfaces with the caliper. It includes ears/tabs that ride on the bracket abutments and may incorporate slots or features for springs and sensors.
• Shim/insulator: A noise- and vibration-dampening layer attached to the back of the plate. Often a multi-layer steel (MLS) or rubberized composite that interrupts vibration paths and helps prevent squeal.
• Underlayer (cushion/insulation layer): A compliant layer between the lining and the backing plate that helps absorb vibration and reduce heat transfer into the caliper. Common on higher-quality pads.
• Bonding and mechanical retention: High-temperature adhesive and/or physical retention (e.g., hooked or staked plate surfaces such as NRS-style mechanical retention) that anchor the lining to the backing plate and resist shear under heavy braking.
• Chamfers and slots: Shaped features in the lining (edge chamfers and central/segment slots) that manage gas and dust, reduce leading-edge vibration, help prevent cracking, and promote even wear.
• Wear indicator: Either a mechanical “squealer” tab that emits a high-pitched noise when the lining nears end-of-life, or an electronic sensor that triggers a dashboard warning. Many European vehicles use plug-in electronic sensors.

Together, these foundational parts ensure the pad generates friction reliably, stays attached to its plate, manages heat and noise, and signals when it’s due for replacement.

Features and finishes you may (or may not) see

Beyond the essentials, manufacturers add features to improve durability, ease installation, and speed break-in. Not every pad includes all of these, but they’re increasingly common in premium and OE-grade offerings.

• Coatings and plating: E-coat, powder coat, or zinc/Geomet-type anti-corrosion finishes on the backing plate to resist rust, especially important for vehicles that see winter road salt or long periods of light braking (e.g., EVs with strong regen).
• Scorched/heat-treated friction surface: A controlled pre-burn that stabilizes the compound and helps the pad bed in quickly with fewer odors and less fade during early use.
• Break-in layer/transfer aid: A thin abrasive or friction-enhancing topcoat on the lining face that speeds formation of a stable transfer film on the rotor during the first drives.
• Integrated springs/anti-rattle clips on the pad: Some pad designs include a spring tang or clip embedded in the backing plate to control pad movement and curb rattle inside the caliper.
• Shim attachment methods: Shims may be bonded, clipped, riveted, or multi-piece to tune noise behavior and serviceability.
• Edge codes and identifiers: Stamped or printed markings indicating friction grade (SAE J866), manufacturing codes, and regulatory compliance (e.g., copper-free labeling).

These enhancements don’t change the basic job of the pad but can meaningfully improve longevity, noise performance, corrosion resistance, and the quality of the first few stops after installation.

What is not part of the pad itself

Brake service often ships with extra hardware, and it’s easy to confuse what’s part of the pad versus separate components. Here’s what typically isn’t considered part of the pad, even though it interacts closely with it.

• Rotor (disc): The iron or composite disc the pad clamps against; separate wear item.
• Caliper and guide pins: The mechanism that squeezes the pads; includes pistons, seals, and slides.
• Bracket abutment clips/hardware: Stainless clips mounted on the bracket that the pad ears slide on; often replaced with pads but not part of the pad assembly.
• Standalone electronic wear sensors: On some models, these are separate leads that insert into the pad and plug into the vehicle harness.

Distinguishing pad components from adjacent hardware helps ensure the right parts are replaced and lubricated, reducing noise and preventing uneven wear.

Why these parts matter

The friction material and its geometry create stopping force, the backing plate and retention features keep everything intact under stress, and the shim and underlayer suppress noise and manage heat. Indicators and finishes assist with maintenance and longevity. Selecting pads with the right mix of these elements—matched to your vehicle, driving style, and climate—yields quieter, safer, and more durable braking.

Summary

A modern brake pad combines a friction lining, steel backing plate, noise-dampening shim, underlayer, bonding/mechanical retention, chamfers and slots, and a wear indicator, with optional coatings and break-in layers. Each piece serves a specific role: generate friction, stay secure, control heat and vibration, and signal end-of-life—together delivering consistent, quiet, and reliable stops.

What is the piece that holds the brake pads called?

This is what’s called the brake caliper. Now that holds well it does two things number one it holds the brake pads.

What are the 4 major parts of a disc brake system?

When it comes to disc braking systems, there are four parts you need to know: The pads, rotors, calipers, and hardware. The system is responsible for… well, braking. However, as with any other component within your vehicle, each aspect of the braking system serves a different purpose.

What is the 30 30 30 rule for brakes?

At ADVICS, our technicians follow the 30-30-30 rule for bedding-in and suggest this as the preferred method. That means performing 30 slow stops from 30 mph, with at least 30 seconds of cool down in between.

What are the components of a brake pad?

Brake pads are a component of disc brakes used in automotive and other applications. Brake pads are composed of steel backing plates with friction material bound to the surface that faces the disc brake rotors.