Comprehensive Knowledge of Brake Pads Industry

Brake pads are the core safety components of the braking system, which convert kinetic energy into thermal energy through friction to achieve vehicle deceleration and stopping. Their performance directly determines braking distance, thermal stability, noise and service life.

1. Basic Structure

A standard brake pad consists of three key parts:

1. Backing Plate: Bears load, ensures installation positioning, and provides strength and heat dissipation.

2. Insulation Layer: Blocks high temperature to protect the caliper piston and oil seal.

3. Friction Block: The core functional layer that determines the braking performance.

2. Main Materials and Comparison

(1) Semi-Metallic (SM)

• Composition: 30%–60% metal fiber + resin + fillers

• Advantages: Heat resistance up to 400℃, excellent heat dissipation, stable under heavy load, cost-effective

• Disadvantages: High noise, heavy dust, easy to damage the brake disc, hard at low temperature

• Application: Commercial vehicles, heavy-duty vehicles, performance cars

(2) Low-Metallic (LM)

• Composition: Low metal + NAO organic system

• Advantages: Smooth braking, low noise, balanced performance at normal temperature

• Disadvantages: Slight dust, obvious high-temperature fade

• Application: Original equipment (OE) for passenger vehicles

(3) Non-Asbestos Organic (NAO)

• Composition: Aramid/glass fiber + resin + non-metallic fillers

• Advantages: Silent, low dust, non-damaging to brake discs, comfortable

• Disadvantages: Low heat resistance, easy to wear under heavy load

• Application: Urban passenger vehicles, light-load driving

(4) Ceramic NAO (Top Choice for Passenger Cars)

• Composition: Ceramic fiber + mineral fillers + low/copper-free formula

• Advantages: Stable friction, heat resistance up to 650℃, silent, low dust, long service life (50,000–100,000 km), protects brake discs

• Disadvantages: Higher cost, slightly soft initial braking at extremely low temperature

• Application: Passenger vehicles, new energy vehicles, high-end matching

(5) Carbon Ceramic / Powder Metallurgy (High-End/Racing)

• Advantages: Ultra-high heat resistance, extreme wear resistance, ultimate performance

• Disadvantages: High cost, not suitable for daily driving

• Application: Supercars, racing cars, special vehicles

3. Key Performance Indicators

• Friction Coefficient: 0.35–0.45 is ideal for passenger cars; too high causes lock-up, too low leads to weak braking

• Thermal Fade: Retention rate of friction coefficient after continuous braking, higher means safer

• Wear Rate: Material consumption speed, affecting service life and disc protection

• Noise & Vibration: Related to formula, chamfering and noise shims

• Shear Strength: Bonding force between friction layer and backing plate, preventing delamination

4. Replacement Cycle & Judgment Criteria

Replacement Threshold

• New pad: 10–12mm

• Early Warning: ≤5mm (recommended replacement)

• Mandatory Replacement: ≤3mm (immediate replacement to avoid disc damage)

Warning Signs

• Sharp metallic squeal (triggered by wear indicator)

• Soft brake, longer braking distance, steering wheel vibration

• Brake warning light on dashboard

Normal Service Life

• Front pads: 30,000–50,000 km (20,000–30,000 km in congested cities)

• Rear pads: 60,000–100,000 km

• New energy vehicles: 80,000–120,000 km for front pads (reduced wear due to kinetic energy recovery)

5. Selection & Installation Tips

• Match vehicle model: Year, displacement, drive type and caliper specification

• Prioritize certifications: ISO 9001, IATF 16949, GB 5763, ECE R90

• Taboos: Mixed models, single-wheel replacement, replacing only one pad

• Installation: Chamfering for noise reduction, lubricating guide pins, gentle running-in within 200 km

6. Industry Standards & Certifications

• National Standard: GB 5763 (Brake Linings for Automobiles)

• EU Standard: ECE R90 (Mandatory certification for replacement parts)

• US Standard: FMVSS 135, SAE standards

• Core Requirements: Stability of friction coefficient, thermal fade, wear rate, shear strength

7. Industrial Chain & Market

• Upstream: Friction materials (60%–80% of cost), backing plates, auxiliary materials

• Midstream: OE matching, after-market (AM)

• Downstream: Passenger vehicles, commercial vehicles, new energy vehicles, rail transit, engineering machinery

• Trends: Copper-free/low-copper, eco-friendly resin, lightweight, intelligent wear monitoring

8. Technology Development Trends

1. Copper-free Formulation: Environmentally compliant, reducing dust and pollution

2. High Heat Stability: Adapt to new energy vehicles and high-speed driving

3. Long Life & Low Dust: 60,000–100,000 km service life, silent and comfortable

4. Intelligent Sensor: Built-in wear monitoring for early warning

5. System Integration: Collaborative optimization with calipers, discs and electronic control systems