Choosing the Right Fiber Disc for Your Application

Fiber discs are one of the most popular forms of abrasive grinding and finishing products. When used properly, they can do just about any grinding application that wheels can do — it all comes down to using the right disc for your application.

But before you decide which fiber disc to use, it’s important to understand what they are and how to properly mount them on a grinder. 

The Disc:

A fiber disc is a single layer coated abrasive applied to a vulcanized fiber backing. United Abrasives/SAIT offers a complete line of fiber discs, from general purpose economical choices to those that contain top-quality grinding aids to reduce heat discoloration on stainless steel and reduce loading on high load applications (like aluminum).

The backing used in our SAIT fiber discs is the highest quality in the industry and it resists tearing and curling. This rigid vulcanized fiber backing permits the disc to be used in more aggressive applications than a cloth or paper backed disc could, allowing higher pressure for maximum stock removal and life.

Our unique fiber disc storage spindle keeps the discs flat, providing the user with ready-to-use discs! It utilizes a lock nut that can be re-tightened after each use creating constant pressure to prevent curling.

SAIT utilizes state-of-the-art coating technology, virgin grain and advanced resins to make the industry standard for fiber discs. People who know, use SAIT!!

The Backing Pad:

In order to properly mount a fiber disc, you MUST use a backing pad. A backing pad provides the necessary support to connect the disc to the grinder. It is important to note that once a backing pad is worn down, it must be replaced to prevent tearing.

One of the most common backing pads, the Spiralcool^TM, features spiral ribs that provide numerous contact points and channels that increase the flow of air behind the disc. This keeps the disc cooler, allows for better performance and ensures a longer life – up to 50% better life than a standard pad!

The SAIT-LOK quick change pad allows for easy mounting of our SAIT-LOK fiber discs which means quick, tool free abrasive changes and minimal downtime. Just twist and go! 

The SAIT Difference: 12 Options to Cover Every Application

As we spoke about in our previous blog, the abrasive grain is what is actually doing the work in any abrasive product. The grain used in a fiber disc determines the disc’s cutting speed, life and cost-ratio. You will find four types of abrasive grains used in SAIT fiber discs:

Aluminum Oxide: Aluminum Oxide is the most common abrasive grain and delivers very good cut rates and durability. It tends to have a lower initial cost for the user, which accounts for its popularity.

Within the SAIT A/O product offering, there are 3 fiber discs:

• AO – Open coat: Economical choice for general purpose grinding and finishing

• 2A – Closed coat: For general purpose grinding and finishing of ferrous and non-ferrous metals

• 3A – Closed coat with grinding aid: For general purpose grinding of stainless steel and aluminum

Zirconium: Zirconium, the most popular grain used in fiber discs, features long life when used in high pressure applications that include blending, deburring and weld removal. In general, Zirconium products tend to have 2-3 times the life of their aluminum oxide equivalents. 

Within the SAIT Zirconium product offering, there are 3 fiber discs:

• AZX: Economical choice for fast grinding and finishing
• Z-Closed coat: For aggressive stock removal and long life on ferrous and non-ferrous metals
• 3Z-Closed coat with grinding aid: For fast and efficient grinding of stainless steel and aluminum

Ceramic: Ceramic grain offers maximum productivity and performance, making it tough to beat.  Ceramic grain removes material easily and quickly and is ideal for users who want to get work done faster, with fewer disc changes.

The unique structure of ceramic grain, with significantly more fracture points, allows for more cutting power. Due to this self-sharpening nature, ceramic features fast stock removal, less friction and cooler grinding. This makes ceramic ideal for use on heat-sensitive materials and high-tensile alloys, as well as carbon steel.

Within the SAIT Ceramic fiber disc product offering, there are 5 fiber discs:

• 7AS – Ceramic Blend: Unique blended ceramic fiber disc for economical grinding
• 7S – Closed Coat: For very aggressive stock removal and exceptional life on carbon steel and alloys. Excels under high pressure.
• 9S – Closed coat with grinding aid: For high performance grinding of stainless steel and aluminum

Coming Soon!!: 7- II and 9- II fiber discs

• 7- II and 9- II: Unique, high concentration ceramic grains utilizes the most advanced grain technology for the highest level of performance. Features extremely fast stock removal, long life and ability to be used in the most demanding applications. These products pair very well with a hard backing pad for maximum performance. These will be available in 36+, 50+, 60+ and 80+ in late 2018.

• 7- II: For best in class performance on carbon steel and other ferrous metals. Ideal for welds, burrs and any application where heavy stock removal is preferred.

• 9- II: For best in class performance on stainless steel and other heat-sensitive metals. Ideal for welds, burrs and any application where heavy stock removal is preferred and minimal heat generation is needed.

Silicon Carbide: Silicon Carbide has a unique grain structure; its abrasive grain can cut very quickly due to the sliver like shape of the grain. This structure, while relatively fragile, makes it ideal to aggressively grind concrete, marble, granite, and other stonework. It performs very well on very hard metals (cast iron, carbide, etc.) and titanium.

• C -Closed Coat: Available in 7” from 16-400 grit for every application from heavy stock removal to fine finishing. Unique recessed center hole prevents the locking nut from marring the workpiece.

Still Need Help?

If you’re still unsure which product is right for your job, check out that product application search we mentioned above (click here to access it), or feel free to contact us directly.