CERAMIC VS SEMI-METALLIC BRAKE PADS

Head to head

Here is how the three compare on the things a driver feels and a technician sees on the rotor. A dash means none of the sources we read compared that cell, so we left it blank.

Every row describes a type of pad, not a part number. Formulas are each maker’s own, so two ceramic pads from different brands will not behave identically, and the lines blur: Raybestos sells a hybrid it describes as the best of ceramic and semi-metallic.

Ceramic: the quiet one

Ceramic pads are what customers mean when they ask for brakes that “don’t make a mess.” Less dust on the wheels, less noise, and the longest life of the three. The trade-off is that they are not the first answer for heavy, repeated heat: Raybestos, for one, builds its performance line on semi-metallic friction.

They cost the most of the three. On a commuter car that is usually money well spent, because the customer comes back less often and complains less about dust.

Semi-metallic: the working one

Semi-metallic pads mix flaked metal into the compound. They are harder than non-metallic pads, more fade-resistant and longer lasting, and they cost more rotor to do it: the rotor wears faster and is replaced sooner. They also need more pedal force to make the same braking torque.

For pickups that tow or haul, semi-metallic is the usual choice. Price the axle on the brake job calculator, and budget for rotors sooner than on a ceramic setup.

Organic and low-metallic

Organic pads, sold as NAO (non-asbestos organic), are synthetic fibres bonded into a composite. They are gentle on rotors, wear out fastest and make plenty of dust. They make sense on a light car driven gently, and they are the cheapest of the three.

“Low-metallic” is a label some makers put on a pad with less metal than a semi-metallic. There is no standard definition behind it, so treat it as a maker’s own category and read that maker’s spec sheet rather than assuming it behaves like either column above.

The A, B and N leaf marks

Copper used to be a standard pad ingredient. It washes off roads in stormwater, and the EPA notes that copper in runoff can harm fish, amphibians, invertebrates and plants. California and Washington passed laws first. On January 21, 2015, the EPA, the states and the industry groups signed the voluntary Copper-Free Brake Initiative: under 5 percent copper by weight in 2021 and 0.5 percent by 2025, plus limits on mercury, lead, cadmium, asbestiform fibres and chromium-six salts.

The LeafMark printed on the box shows which level a pad meets. Wagner’s explanation: the darker the leaf, the more levels the pad meets.

The leaf tells you about the environment, not about stopping. An N-marked pad can be ceramic or semi-metallic, so the head-to-head table above still applies.

When the OE spec decides it

Pad makers sell “application-matched” ceramic or semi-metallic friction, meaning the type follows what the vehicle was engineered for. That matters most on heavy trucks and SUVs, on performance cars with big rotors, and on anything under warranty, where a different friction type gives the customer a reason to blame the brakes for the next noise. The wider argument is in OEM vs aftermarket parts.

On an ordinary car out of warranty, moving from semi-metallic to ceramic for less dust is fine. Write the change down and tell the customer. If the line is due as well, the brake line repair guide covers it, and the brake fluid flush is worth adding while the wheels are off.