How to Select the Right Flap Disc for Your Project

When it comes to flap discs, there’s a variety of discs available in today’s marketplace. Let’s start by understanding the various components of a flap disc, so you know how to select the right disc for the right task:

Flap Disc Shape

Is stock removal your primary objective, or do you want a smooth finish? Choosing the right disc shape is the single-most important variable, and the shape will help you effectively achieve your results. Flap discs are almost always used on right angle grinders, and they are applied to your work at an angle or parallel to it. Flap discs are available in two shapes: conical or flat-shape.

• Conical flap disc: Conical flap discs are your best friends when you need to remove a lot of material in a small amount of time. They can be used for edge-working as well as on contoured applications. The flaps in a conical flap disc are angled. As a result, these discs offer a greater surface area for stock removal on horizontal surfaces.

• Flat flap disc: While conical discs are great for rapid stock removal, flat flap discs are best for blending and superior finishing. They are mostly used on flat surfaces. The flaps of a flap disc are adhered to a backing plate which provides stability during operation.

• Fiberglass: Being strong, durable, lightweight and safe, fiberglass is the most popular material choice. Fiberglass creates a strong bond with adhesives and does not contaminate the working surface. This type of plate also gets consumed during use, and it absorbs vibration very well. Remember, fiberglass backing is made out of layers of fiberglass that are mesh-bonded and pressed together. With more layers and a higher mesh density, the backing will be stronger and more durable — this is an important consideration when you’re examining the detailed specs of a flap disc.

• Plastic: Another popular backing material is plastic, and nylon is the most commonly used plastic. These backings can be trimmed which allow longer usage of flaps, specifically during blending and finishing. These days, plastic is becoming an increasingly attractive choice due to its conformability and costs.

• Metal: Metal backing plates are the safest choice, and they’re great when you need extra strength and firm support. Aluminum is a commonly used metal. Since metal plates are expensive, they should also be used where they make the most sense. For example, when working with flap discs on concrete or stone applications, use flap discs with metals for strong support and better performance. Metals don’t get consumed during use, but metal plates can be easily recycled when a flap disc is past its useful life.

• Ceramic Alumina: This material is great for stainless steel or alloy metals application. With Ceramic Alumina, the grit material ruptures at a micro level during operation. This produces a constant supply of sharp cutting surfaces. As a result, it enables faster cutting while allowing the entire grain to be used. As the entire grain is getting used up in the cutting process, these discs offer higher durability.

• Zirconia Alumina: This is a blend of Zirconia and Aluminum Oxide grain, and it’s great for carbon and mild steel application. Zirconia Alumina costs less than Ceramic Alumina, and it provides a great cut rate for the cost.

• Aluminum Oxide: This is the original grit material used in the 1970s when flap discs were first introduced. It’s also the lowest-cost option. Today, it is recommended for smaller jobs where the product being produced is low-value.