When most people think of abrasives, they probably think first about a standard grinding wheel or disc. So when does it make sense to change course and instead use a flap disc or flap wheel?
Flap discs are used to conform and shape metal. They have densely layered abrasive cloth flaps that can shape certain metals while leaving a finished look. They are most commonly used in welding, machining, heavy-duty equipment, industrial maintenance, agriculture and food production.
Flap discs and flap wheels offer the main advantage of being able to provide finder finishes than grinding wheels and can perform on uneven surfaces, but they also have several other benefits:
- Ability to vary pressure as needed to provide a coarser or smoother finish
- Cooler operation, which means you’re less likely to leave scorch or heat marks
- Less vibration and fatigue for more comfortable operation
- Improved safety because there are no pieces to shatter or fly off
- Better finish with less gouging for improved appearance
Flap discs don’t offer the same level of metal removal as standard grinding wheels, and they might wear out faster and cut more slowly, so it’s important to weigh these advantages and disadvantages to determine if a flap disc or wheel is right for your job.
Standard flap discs last up to 25 times longer than aluminum oxide resin fiber discs when used to smooth down welds after using grinding wheels. The can grind and finish simultaneously. Just apply heavier pressure for aggressive grinding and lighter pressure for a finer finish.
The Kim-Flex line provides fast cutting action with flexible discs that conform to curved, contoured and irregular surfaces. They come in a variety of grits, diameters and densities so you can get the right abrasive for your job.
The line varies 4 to 7 inches in diameter and has grits from 24 to 120. A lower grit number is best for standard grinding, with higher grit numbers providing smoother finishes. You should use a flap disc one or two grits coarser than a conventional disc for best results.
Discs with higher density last longer, but a standard density disc offers the ability to be more aggressive in stock removal.
A quality abrasive offers longer life, avoiding the need to frequently change discs. Quality flap discs also can grind and finish simultaneously, meaning you don’t have to switch between two kinds of discs.
Even though a standard flap disc can do a lot of great things, sometimes the job demands an even more powerful level of abrasive. That’s where ceramic discs such as Dark-Fire and Crimson-Fire come into play, offering longer life and even more stock removal.
Dark-Fire flap discs are the top of the line with a proprietary ceramic matrix that provides exceptional service life and aggressive grinding power. These discs deliver a high cut rate, even on tough alloys like stainless steel, cobalt and titanium. They also are designed with a high surface area and excellent heat sensitivity.
Crimson-Fire flap discs come with a premium ceramic grain that offers superior performance, even on tough alloys.
One specialized type of flap disc allows you to see the work piece while grinding. Kimball Midwest offers this feature in its V.S.R. Flap Discs, which allow you to see through the wheel while it is in use. (V.S.R. stands for Visible Stock Removal.)
Flap wheels are similar to flap discs in that they shape metal, but flap wheels are designed to allow you to grind and finish hard-to-access areas such as the inside of pipes or tubes.
Like discs, they come in a variety of sizes, grits, diameters and widths depending on the application.
Standard flap wheels, made of aluminum oxide abrasive cloth, provide consistent grinding and finishing action for applications including final metal finishing, deburring, edge blending, cleaning and finishing for painting and plating.
Like for flap discs, the Crimson-Fire line provides an extra level of performance with a crystalline abrasive structure ideal for quick and effective grinding and finishing.
Overall, flap discs and flap wheels offer a nice combination of grinding and finishing power and provide a useful tool for many abrasive applications.