In most cases, you’re most likely to find clutches and their accessories as a kit because many times, multiple problems arise at once. While the pressure and clutch plate are similar, they aren’t quite the same. The pressure plates are what attaches to the engine and the clutch plates attach to the transmission. As such, they are more likely to wear faster than pressure plates. However, suppliers may choose to offer kits with both products, (or multiple products), making it easier and quicker to replace what is causing the problem.
Materials
The plates or discs are usually made of steel, but they will have a friction material applied. Suppliers are likely to carry multiple varieties to ensure that they can help customers with many vehicles. Therefore, you can find organic materials, with a mixture of fiberglass and others, woven or molded onto the friction pad. You can also find Kevlar or Twaron, ceramic, feramic, and feramAlloy, all of which may be available from the same supplier.
What Manufacturers Consider
Before the clutch plate goes to the suppliers (where you buy them), the manufacturer or designer must compare all the various materials by using four metrics that will determine how the product works. They will likely focus on the static friction coefficient, which will determine how well your disc holds onto the flywheel while accelerating. Likewise, they’ll focus on dynamic friction coefficients, which will determine how abruptly or smoothly the disc grabs the flywheel.
They’ll also focus on clamping force and fade temperature. All four options will help to ensure that the clutch plate the suppliers provide to their customers is going to work for extended periods. Likewise, they may also offer warranties to show how well they believe these plates will perform, usually determined by how much you drive.
