The 3 types of brake pads and how they differ

Learn the difference between the 3 types of brake pads

There are three types of brake pads: Organic without asbestos, called non-asbestos organic (NAO), semi-metallic, and ceramic. Some companies make a low-metallic NAO, but that’s becoming obsolete

Although there are three types of brake pad material, they all use one of only two types of friction technologies: adherent or abrasive (although most use a combination of the two types). See this post on the two types of braking technologies.

Non-asbestos organic (NAO) brake pads

NAO pads were once the most prevalent type used for cars and light trucks, accounting for use in more than 60% of all cars and trucks. But that’s changed with the introduction of ceramic brake pads. Today, ceramic brake pads are used on over 70% of all new cars.

NAO brake pads are made from organic materials such as:

• Fiber
• Glass
• Phenolic resin
• Binding agents

NAO is the softest of the three types. They brake the vehicle using ADHERENT friction. Adherent friction technology wears the brake pads wear faster than the rotor.

The advantages of NAO brake pads:

• They are quiet

The disadvantages of NAO brake pads:

• They wear faster than semi-metallic and ceramic brake pads
• They create a lot of brake dust that discolors your wheels

Semi-Metallic brake pads

Semi-metallic brake pads are made with metal fibers to generate heat while also dissipating heat away from the rotor. Semi-metallic brake pads consist of between 30% and 65% metal.  Semi-metallic brake pads include:

• zirconium silicate
• steel wool
• wire
• copper (new EPA rules require the reduction/elimination of copper in brake pads)
• Whiting (Chalk)
• Bronze powder
• Graphite
• Vermiculite
• Phenolic resin (Cashew shell oil)
• Rubber particles
• Friction Dust
• Sand

Semi-metallic brakes provide the most stopping power of the three types of brake pads, so they’re often used on heavy SUVs and light trucks. Semi-metallic brake pads use ABRASIVE friction technology to stop the vehicle. Because of that, semi-metallic brake pads wear the rotor faster than the brake pads.

Semi-metallic brake pads don’t work as well when cold, but offer far more fade resistance in hard stops compared to either NAO or ceramic. They tend to be cheaper than ceramic brake pads but cost more than NAO pads

Because of their superior braking power, semi-Metallic brake pads are best suited braking large vehicles of vehicles carrying heavy loads. They’re also used in high-performance race cars.

The advantages of semi-metallic:

• They provide the best stopping power
• They have the highest fade resistance

The disadvantages of semi-metallic:

• They create the most brake noise (squeal and grinding)
• They create brake dust
• They wear out the rotors faster
• They have to heat up to provide the best braking
• They perform poorly when cold

Ceramic brake pads

Ceramic brake pads use ADHERENT friction technology for film-on-film braking. They provide good stopping power, low noise, and low rotor wear with less brake dust. Ceramic brake pads offer good stopping power when cold but have less fade resistance than semi-metallic brake pads when hot.

Ceramic brake pads are made with:

• Ceramic strands made from high-quality ceramic-silicon carbide. alumina and boron carbide,
• bronze powder
• Graphite
• Vermiculite
• Phenolic resin (Cashew shell oil)
• Rubber particles
• Friction Dust
• Sand

The advantages of ceramic brake pads:

• They make less noise than semi-metallic brake pads
• They’re harder than NAO pads, but softer than semi-metallic
• They’re easier on rotors than semi-metallic
• They produce much less dust than either semi-metallic or NAO

The disadvantages of ceramic brake pads:

• They’re more expensive than NAO and some semi-metallic brake pads
• They have lower fade resistance than semi-metallic brake pads.

If your vehicle came with semi-metallic, think twice about changing to ceramic because they may reduce your stopping power.

Each of the different types of brake pads come in different quality levels

See this article on the differences in brake pad quality levels

Which type of brake pad friction material should you choose?

Generally speaking, of all the different types of brake pads that will fit your vehicle, you should stick with the type of brake pad that came on your vehicle from the factory.  If you change to a different brake pad chemistry, you will get different braking performance.

For example, if you switch to a ceramic brake pad in place of the semi-metallic pads that were the original equipment of your truck, you’ll get quieter operation, less rotor wear, and less brake dust. But you’ll also experience decreased high-temperature braking performance. See, there’s no free lunch here. The engineers choose a particular brake pad chemistry for a reason—to get the best braking performance for the vehicle, based on the vehicle’s weight and design and Federal new car braking requirements.

Don’t buy the myth that Ceramic is always the best brake pad

About 60% of all new vehicles come with ceramic brake pads. But that doesn’t mean the other 40% have lousy brake pads. Carmakers have been switching to ceramic brake pads to reduce consumer complaints about noise and brake dust. The braking systems on those vehicles are designed for ceramic pads. Yet semi-metallic pads often outperform ceramic in terms of sheer stopping power. Plus, just like the word “premium,” there’s really no industry standard for the word ceramic. If your vehicle came with ceramic pads and you install an economy or OE ceramic replacement that doesn’t match the quality of the real OE pad, you’ll be disappointed with braking and product life. In other words, not all ceramic pads are created equal, and they’re not always an upgrade from semi-metallic pads.

For more information on the 3 types of brake pads visit brake manufacturer Mat Foundry

©. 2019 Rick Muscoplat