What Is the Metal Thing on a Brake Pad?

In most cases, the metal thing on a brake pad is the wear indicator (often called a “squealer”)—a small metal tab that contacts the rotor and makes a high-pitched noise when the pad’s friction material is nearly worn out. Depending on where you’re looking, it could also be a backing plate, an anti-squeal shim on the back of the pad, or an anti-rattle/abutment clip in the caliper bracket. Understanding which part you’re seeing helps you decide whether it’s time for maintenance or just a normal component of the brake assembly.

The Common Culprit: Wear-Indicator Tab (“Squealer”)

The most common exposed metal piece attached to a brake pad is the mechanical wear indicator tab. It’s a small finger of steel affixed to the pad’s backing plate at the edge of the friction material. When pad thickness drops to roughly 2–3 mm, the rotating rotor brushes the tab, producing a sharp, consistent squeal that increases with wheel speed and often gets louder during light braking. That audible warning is your cue to plan pad replacement soon to prevent grinding, long stopping distances, or rotor damage.

Symptoms and What to Do

If you’re hearing a steady squeal that starts or intensifies with light brake application—or you notice a thin metal finger near the edge of the pad contacting the rotor—you’re likely hearing the wear indicator doing its job. Quick checks and steps can keep your braking system safe and quiet.

• Inspect pad thickness on both inner and outer pads; replace if the friction material is at or below about 3 mm.
• Check the rotor surface for grooves or a pronounced ridge; consider resurfacing or replacing rotors if they’re scored or below minimum thickness.
• Verify the indicator tab orientation matches the manufacturer’s specification (inner vs. outer pad, leading vs. trailing edge).
• Do not bend, cut, or remove the tab—it’s a safety feature.
• If you have an electronic wear sensor (a wire/harness), inspect and replace it when doing pads, as many are single-use.

Addressing the squeal promptly prevents metal-on-metal contact, reduces repair costs, and maintains predictable braking performance.

Other Metal Pieces You Might See

Brake pads and calipers include several metal components besides the wear tab. Knowing these helps you identify what you’re looking at and whether anything is missing or misinstalled.

• Backing plate: The thick steel plate bonded to the friction material—this is the structural body of the pad.
• Anti-squeal shim: A thin metal plate (often multi-layered with a coating) adhered to the pad’s back to damp vibration and reduce noise.
• Abutment clips (hardware): Stainless clips that snap into the caliper bracket where the pad ears slide; they prevent chatter and ensure smooth pad movement.
• Pad retaining spring/anti-rattle spring: A visible spring or cross-clip that spans both pads on some caliper designs to keep tension and reduce rattles.
• Guide pins/retaining pins and cotter clips: Pins that secure pads in fixed calipers; cotter clips or split pins lock them in place.
• Electronic wear sensor: A small plastic sensor with a wire harness that slots into the pad; when the pad wears, it completes a circuit to trigger a dash warning.

All of these parts play a role in noise control, pad alignment, and safety—missing or corroded hardware can cause uneven wear, noise, or reduced braking performance.

How to Identify Which Metal Part You’re Seeing

Use location and appearance to distinguish the wear tab from other hardware. A quick visual checklist can clear up most confusion.

• Small finger on the edge of the friction material: Mechanical wear indicator tab.
• Thin sheet covering the back of the pad (facing the caliper piston): Anti-squeal shim.
• Shiny stainless inserts in the caliper bracket where pads slide: Abutment clips (hardware kit).
• Wire attached to the pad with a plastic insert: Electronic wear sensor.
• Long pin(s) running through the pads with a spring plate and cotter clip: Retaining pins and anti-rattle spring (common on fixed calipers and many performance brakes).

Identifying the part correctly helps you decide whether the noise is a normal wear alert, a hardware issue, or simply the appearance of a standard component.

Safety and Maintenance Tips

Proper brake service goes beyond swapping pads. Following best practices ensures quiet operation and consistent stopping power.

• Replace pads before they reach the wear tab if you notice rapid wear or heavy loads (towing, track use).
• Inspect and replace hardware (abutment clips, springs, shims) and clean/lubricate slide points with high-temp brake grease—avoid contaminating pad friction surfaces and rotors.
• Service caliper slide pins (floating calipers) with the correct lubricant and confirm free movement.
• Measure rotor thickness and runout; replace or machine only if within manufacturer limits.
• Bed-in new pads and rotors per the manufacturer’s procedure to minimize noise and maximize performance.
• Verify brake fluid level and condition; replace fluid at the recommended interval to prevent boiling and corrosion.
• For electronic sensors, reset the service indicator after replacement using the vehicle’s procedure or a scan tool.
• Torque wheels to spec after service to avoid rotor distortion and vibration.

These steps reduce noise complaints, extend component life, and keep braking performance predictable in all conditions.

FAQs

Is the squeal dangerous by itself?

The squeal from a mechanical wear indicator isn’t immediately dangerous, but it means the pads are near the end of life. Replace them soon to avoid rotor damage and reduced braking power.

What if I hear grinding?

Grinding typically means the pad is worn past the friction material and metal is contacting the rotor. Stop driving and repair immediately to avoid costly damage and unsafe braking.

Can I remove or bend the tab to stop the noise?

No. The tab is a safety feature. Bending or removing it masks a maintenance need and can lead to rotor damage and unsafe operation.

Do all cars have a metal squealer tab?

Most do, but some rely solely on electronic wear sensors. Many modern European cars include both an electronic sensor and shims/hardware for noise control.

Summary

The “metal thing” on a brake pad is most often a mechanical wear indicator tab designed to squeal when the pad is nearly worn out. Depending on where it’s located, it could also be a backing plate, anti-squeal shim, abutment clip, or anti-rattle spring. Identify the part by its position and shape, inspect pad thickness, and replace worn components promptly. Proper hardware, lubrication, and rotor checks ensure quiet, safe, and reliable braking.

Do you remove the metal plate on brake pads?

Yeah you keep the the shims on. They shouldn’t be rattling in the calipers though.

What is the metal clip on brake pads for?

A brake pad clip is either a wear indicator, a metal tab designed to make a squealing noise when the brake pads are worn low, or a anti-rattle clip, which is a spring-steel clip that holds the brake pads in place, reduces noise and vibration, and ensures they move freely in the caliper. Some brake pads only have wear indicators, while others have both wear indicators and anti-rattle clips. 
Wear Indicators 

• Purpose: These are tabs on some brake pads that signal when the pads are worn down to a level where they need to be replaced.
• How they work: When the pad material wears away, the metal tab begins to contact the rotor, creating an audible squealing or scraping sound.
• Benefit: The noise is a warning that helps prevent further damage to the rotor by prompting you to replace the pads before they wear down to the steel backing plate.

Anti-Rattle Clips (Retention Clips)

• Purpose: These are spring-loaded clips that apply light spring pressure to the brake pads. 
• How they work: They help hold the brake pads securely in their proper position within the caliper bracket. 
• Benefits:
  • Reduces noise: They eliminate or reduce brake squeal and chatter by preventing the pads from vibrating and rattling against the caliper. 
  • Ensures proper movement: By keeping the pads aligned and free from the caliper when the brakes are disengaged, they help the system function correctly. 

Why only one pad might have a clip

• Wear indicator location: The wear indicator is typically placed on the inner pad, on the side that contacts the piston. 
• Anti-rattle clip type: Some brake systems use different types of clips, and a car may only have a single anti-rattle clip on one of the pads. 
• Need for replacement: Both types of clips should be replaced with new ones whenever you change your brake pads to ensure they continue to function properly. 

Are brake pad squealers necessary?

If you ignore your squealer, you’re in for a grind (and likely a more expensive repair). Grinding or scraping indicates metal on metal contact — no brake pad friction material to stand in the way. If you let the grinding go too long, you’ll likely need to replace the rotors along with the brake pads.

What is the metal tab on brake pads for?

The metal tab on brake pads is a brake wear indicator, also known as a “squealer” or “wear sensor”. When the friction material on the brake pad wears down to a certain minimum thickness, this metal tab contacts the brake rotor, creating an annoying high-pitched squealing noise. This sound is a mechanical alert to the driver that the brake pads are worn and need to be replaced soon.
 
This video explains how the metal tab on a brake pad works: 57sdial2fastYouTube · Jul 4, 2016
How it works

• Acoustic Warning: The tab is a mechanical component that doesn’t trigger a dashboard light. 
• Contact with Rotor: When the brake pad wears thin, the tab rubs against the rotating brake disc. 
• Squealing Sound: This contact produces a loud, high-pitched squeal, which is more pronounced when you are not pressing the brake pedal. 

Purpose

• Early Warning: The squealing sound serves as an early warning sign that the brake pads are significantly worn and require immediate maintenance. 
• Safety Feature: It helps to prevent excessive brake wear and ensures the braking system remains effective, promoting safety. 
• Mechanical Alert: It is a common feature on many vehicles, providing a simple, audible way to know when brake replacement is necessary. 

This video explains the purpose of brake wear indicators: 55sRaybestos BrakesYouTube · Aug 23, 2018
Placement 

• The wear indicator tab is typically located on the inboard brake pad of a set, though this can vary by vehicle manufacturer.
• It’s important to consult your vehicle’s service manual or inspect the original setup to ensure the tab is placed correctly if you are replacing the pads yourself.