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18 March, 2021

Flap discs vs grinding discs

While flap discs and grinding discs are similar in nature, they are both used on angle grinders to shape metal; there are crucial differences which determine when and how they should be used. Grinding discs are traditionally the preferred option for removing materials but they can also be used for surface preparation. They are coarser and quicker at evening out surfaces than zirconia flap discs however they do not leave the smoothest finish. Flap discs, while also used for shaping metal, help you achieve a smooth and even surface when finished. We’ll delve into more information about the differences below to help you find the right abrasive disc for your grinder. Once you know what you are looking for, we stock both products so why not take a look at our product ranges. We only use high performance products designed to last longer so you get even better value.

What are grinding discs and when are they used?

Grinding discs are used to grind away materials on metal and stone. They are used commonly to grind welds and prep metal edges for welding. If you are looking to achieve high stock removal, grinding discs are traditionally the most suitable option.

In regard to their appearance, grinding discs have a thick coarse appearance. They leave uneven results, but they quickly remove materials helping you to get the job done.

What are flap discs and when are they used?

Flap discs are also used for grinding metal as well as deburring, blending and finishing. They are a much more versatile product. They get their name from their appearance as flap discs feature several overlapping layers of abrasive on their surface. These flaps help the discs last longer.

There are several types of flap disc shapes, sizes and grits to get your head around, but ceramic flap discs are the best performance product around and they suit all metal types including aluminium. Flap discs are slower at removing stock; they will however give you a smoother even finish, ideal for if you need to paint the metal after. They also have other advantages over grinding discs when it comes to operation and results. If you were looking at flap discs for stock removal, you would want to look at conical shaped flap discs as their shape helps remove materials more quickly.

The main benefits of flap discs over grinding discs however are:

  • Less re-work. Flap discs provide cooler cutting so there is less need for re-work.
  • Faster grinding. The new Cibo Ceramics FTC Ultimate Flap discs will out grind flap discs, especially when grinding weld preps on steel plate and sheet.
  • No gouging. Grinding discs are aggressive and leave a rough finish. There is also a chance the metal could be damaged with grinding discs. Flap discs offer a smoother consistent finish.
  • Quieter and less vibrations make flap discs more comfortable to work with.
  • Less pressure needed to achieve desired results.
  • Cost-effective as they need reduce your labour costs.

Grinding discs vs flap discs: which is better?

It doesn’t necessarily need to be an either-or question. Both have some crossover and both and have their own benefits. They can be used together however to help get the most from your project. Often grinding discs are used for quick stock removal then followed by flap discs for a smooth and blended finish. If you do not need to worry about the finish, then you’d just opt for a grinding disc as that would offer quicker results. If you want to do a full grinding and polishing job all in one, you could do so with just a flap disc. It might take longer but flap discs are designed for the operator to use them comfortably for a period of time.

Should I choose a flap disc or a grinding disc for heavy grinding?

We would recommend a 40 grit Ceramic flap disc every time. They cut faster, leave a better finish and have much lower vibration than a grinding disc.

Particularly when weld prep grinding you often need to grind away mill scale.  Zirconia flap discs do not have the cutting power and grinding discs take a long time to grind the whole job because you can only grind over a very small contact area.  Ceramic flap discs can grind over a larger surface area, they will cut through the mill scale quicker and leave a better finish which will save welding wire costs.

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