One of the most important pieces of equipment a car needs to adequately function is good brakes. And with that, brake pads. They really are a critical component of vehicle safety, but not all of them are created equal, and knowing a bit of information about how different types of brake pads are designed and what that means for your vehicle’s performance can save a lot of headaches and prevent accidents, as well as have significant consequences for durability, safety, and effectiveness, especially in demanding conditions.
To understand current brake pads better, it is important to see where they came from. In the early days of automotive design, friction materials were mechanically attached to the backing plate using rivets. While a reliable method, the rivets created holes in the material, which led to uneven heat distribution and pressure points, which is why over time they were replaced by adhesives.
Since adhesives had a smooth, uninterrupted bonding surface they improved heat distribution and eliminated the need for holes. Along with it, manufacturers also began using small indentations, called “I am holes,” in the backing plate. When the friction material was pressed onto the plate, some material would flow into these holes, creating an additional mechanical bond.
But just because adhesive was better for everyday cars it did not mean that mechanical attachments were rendered obsolete. In fact, they are still specified for heavy-duty trucks, towing vehicles, and even performance-oriented sports cars where higher stresses and temperatures demand a more robust solution. This means that each method has pros and cons and which one is best for you will depend on many factors.
Mechanical Attachment break pads vs Adhesive
Mechanical attachment uses metal hooks or other features to physically anchor the friction material to the backing plate. Unlike adhesives, this method does not rely on chemical bonding, which can degrade over time or at high temperatures, making them particularly valuable in demanding applications where heat and stress are at their peak. Adhesives have their limitations. When brake pads are exposed to sustained high temperatures, such as during heavy braking in towing or performance scenarios, adhesives can break down compromising performance, which is why mechanical attachment wins out in these situations.
The difference between the two types is clear in theory, but when it comes to reality, how different is the performance really. On tests conducted on various brake pads, including original equipment (OE) and aftermarket options, the pads were heated to 550°F to simulate the conditions of heavy use, then subjected to shear tests to measure the force needed to separate the friction material from the backing plate. The tests showed some interesting results.
- Mechanical Attachment: Pads using mechanical attachment consistently maintained their bond, even after several days of high-heat exposure. The friction material itself often failed before the attachment did, proving the method’s reliability.
- Adhesives with I Am Holes: While better than adhesive-only designs, these still underperformed compared to mechanical attachment. The bond weakened significantly after prolonged heat exposure.
- Adhesive-Only Pads: These showed the most significant degradation. The adhesive layer became the failure point, causing the friction material to detach entirely from the backing plate.
Real-World Implications
Most people that change out their brake pads will get whatever the mechanic in charge of the process will install, but for those enterprising individuals that want to do it themselves or get something that is better for whatever activity they are planning on taking on (like racing their car on the weekend) it is important to have a basic understanding of each type and how they could impact the way the car behaves. If you are purchasing new brake pads yourself, pay attention to the specifications of the brands, as it can be easy to be confused.
