Choosing the Right Sanding Disc

Sep 11th 2019

What Are Sanding Discs? Help choosing the best sanding discs

Sanding is a crucial step in woodworking, metalworking, and many other industries. The type of sanding disc you choose can significantly impact the efficiency and quality of your work. At Empire Abrasives, we understand the importance of using the right sanding disc for the job at hand.

With so many different options available (like type of sanding disc, different abrasive grains, grit size, bonding types, etc.), selecting the right sanding disc can get overwhelming pretty quickly. That's why we've put together this comprehensive guide to help you choose the best sanding disc for your needs. Whether you're a professional fabricator or a DIY enthusiast, we have the knowledge and expertise to guide you through the process.

In this blog post, we will guide you through the process of choosing the right sanding disc, exploring the different types and their applications. We will help you navigate factors like grit size, material compatibility, and disc attachment methods. We'll also provide tips and advice on how to use them safely and effectively. With this helpful guide, you'll have a clear understanding so you can make a better decision when choosing the best disc for sanding, and you'll be able to achieve the best results every time.

What Are Sanding Discs?

Sanding discs are the part of a sander that actually does all the hard work. There's a ton of different discs for different jobs and getting to know the exact type that you need for the work you have to do is vital for anybody using a sander at work or at home.

Choosing the right disc for the job is essential, as failure to do so can result in a poor-quality finish, or damage to what you're trying to sand. Thankfully, we stock a variety of different types of sanding discs and have something in stock to suit your requirements, whatever they are.

It can be a little confusing, what with all the different kinds of sanding discs available on the market today. Thankfully, this guide details the different kinds of sanding disks available from Empire Abrasives and what they're best suited for use on. We will help you to ensure you're using the right sanding discs for the job every time, and as such, minimizing damage to your stock while getting the best value for money possible.

Common Sanding Disc Tools

Angle grinder

Angle Grinder

An angle grinder is one of the most popular tools owned by most fabricators. An angle grinder is a handheld power tool that plugs into an electrical outlet, new ones are available that work with a lithium battery. The main difference in most angle grinders is the amount of power they have and the type of switch. Many welders prefer paddle trigger models over switches because they are much safer if your hands removed from the grinder.

The angle grinder is so popular because it can be modified to take many different types of abrasives discs, cut off wheels and even polishing discs. Just like the many sanding discs on the market angle grinders are available in many different sizes.

Angle grinders are popular but also extremely dangerous if proper precautions aren’t taken when using them. Always use your guard while engaging the grinder, never wear loose clothing while grinding and always wear proper PPE.

Die Grinder

Die Grinder

Die Grinder are typically air powered but electric options are also available. This type of grinder usually takes smaller discs like Roloc wheels or mini cut off wheels. Not only is the die grinder smaller than a typical angle grinder but it spins much faster. There are two types of common die grinders that are either configured with a straight body or an angled body.

This tool is popular because it offers fast work in extremely hard to reach places. When using a die grinder with sanding discs make sure to use the correct backing pad.

Bosch orbital sander photo

Orbital Sander

Orbital Sanders and Random Orbital Sanders are handheld tools that move with a circular motion so not to leave swirls marks on the workpiece. Random just means the disc moves from side to side as it does its rotations. Both types of Orbital sanders are used for finishing and polishing, usually not grinding. This type of sander uses a thinner disc made of paper or cloth with either an adhesive back or hook & loop. This tool is a favorite among woodworkers and auto body professionals.

Worker using a stationary disc sander in a workshop with sparks flying, illustrating proper use and safety gear

Stationary Disc Sanders

Stationary discs sanders can usually be found configured on a pedestal, workbench or on combo belt grinder machines. These disc sanders usually require a more rugged PSA disc and range anywhere from 6” to 14” in size. Dissimilar to the other types of sanders that require you to hold the machine and apply pressure to the workpiece, the wheel with the abrasive will spin, while the user rests the workpiece in front slightly applying pressure to the wheel.

An array of rotary tool attachments including sanding discs, grinding bits, and polishing wheels laid out next to a rotary tool, showcasing the versatility of the tool for detailed work

Rotary Tools

Rotary tools, like Dremel, offer multi-tasking abilities, prized for their high-speed rotation and versatility. Unlike the more powerful angle and die grinders, rotary tools are electric, often cordless, designed for precision work that larger tools cannot achieve. They accommodate a wide array of attachments, from sanding discs to polishing pads, making them ideal for intricate jobs. Perfect for detailed crafting, woodworking, and hobby projects, rotary tools offer precision where it counts.

Different Types of Sanding Discs

Resin Fiber Discs

Resin fiber discs

Resin fiber discs are generally used for blending, grinding, deburring, and finishing metals. Commonly used on an angle grinder with an appropriate backing pad. Resin fiber discs are heavy-duty and abrasive, and are expertly manufactured for a range of applications ranging from surface blending to heavy stock removal. The sturdy fiber backing adds strength to the disc and ensure that they remain rigid when in use, which reduces the chance of errors and breakage.

Fiber discs that feature a center hole for mounting are the most popular kind of discs that are used on electric or air right angle grinders. Resin fiber discs are a good choice for people looking to remove rust and burrs from a variety of metals, such as steel.

Resin fiber discs are an excellent cost effective alternative compared to other types of sanding and grinding discs. Available in a wide range of sizes, grits and materials making them a good choice for many different applications.
Shop Fiber Discs

Flap Discs

Flap discs

Flap discs are an innovative grinding wheel using coated abrasives. This gives you more versatility on the work piece and a softer grind. These discs are used on an angle grinder available in various sizes, materials and ranges of grits. They’re one of the most popular abrasives among welders and metal fabricators due to their ability to smooth out welds, remove mill scale, rust and their aggressive stock removal.

Flap discs are made up of little pieces of sandpaper that are fixed to a firm backing. Instead of being a single piece of sandpaper, they're made of multiple pieces of sandpaper. This not only increases the effectiveness, but also the durability of the discs.

Depending on how coarse the paper that's used is, flap discs are great for removing rust from metal or polishing metal. Flap discs are great for steel, aluminum, and a ton of other metals. The two common styles of flap discs are Type 27 (flat) and Type 29 (contoured). Flap sanding discs are a resilient choice for people looking to sand or polish metal surfaces and offer great value for money thanks to their sturdy composition.
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Hook and Loop Discs

Hook and loop discs

Hook and loop sanding discs are made up of cloth or paper with a backing material not dissimilar to Velcro. There are a system of hooks and loops that are used to affix the sanding disc to the sander. This makes it extremely easy to change the disc, without having to sacrifice on the quality of disc used. If your sander isn't made to be used with hook and loop sanding discs, you can purchase a converter pad which will enable them to fit on your sander.

The most common shape of hook and loop sandpaper is a disc. Hook and loop sanding discs are extremely versatile in the sense that you can buy them in a variety of different grades, from coarse to superfine. What this means is that they're suitable for a variety of work on a variety of surfaces, from wood to metal and almost everything in between.

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Quick Change Discs

Quick change discs

Quick change discs are the go-to choice for grinding, deburring, and blending in small areas and tight corners. The simple to use fastening system makes quick change discs the ideal option for users looking to maximize their productivity. Quick change discs are usually used for a number of purposes on carbon steel, stainless steel, and aluminum. For example, a quick change disc may be used to remove a weld and prepare a piece of carbon steel for its next step in production.

These quick change discs are available in a variety of different sizes and grades which makes them perfect for general use sanding, such as blending, breaking edges, and removing machine marks. These discs are best suited for smaller jobs, unlike PSA discs which are suited to longer, more sustained work.

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PSA Discs

PSA Discs for sanding - (pressure sensitive adhesive)

PSA (short for pressure sensitive adhesive) sanding discs have a sticky back and is good when used on large jobs that are likely to wear out the sandpaper. These types of discs are suitable for prolonged usage, with many workshops opting to use them until the abrasive is completely spent. PSA discs are best suited for use on wood, fiberglass or metal, depending on the coarseness of the disc selected.

Usually sold in rolls or boxes of individual discs. PSA discs are very popular among woodworkers and auto body professionals that typically work on flat surfaces.

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Semi-Flexible Discs

Semi flexible grinding discs

Semi-flexible discs are extremely resilient grinding discs that have been specially designed for the toughest of jobs. They can do the most aggressive forms of stock removal on stone and iron that you may struggle to do with less sturdy discs. Semi-flexible discs are durable and boast an exceptionally long usage life.

Only the best materials go into making the semi-flexible discs that we stock, so you can be sure that they're up to any job that you decide to throw at them. The contoured surface of semi-flexible discs are expertly designed to remove high levels of stock over a wide range of applications. These discs are available in different sizes so there's sure to be something in stock to suit your requirements.

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Surface Conditioning Discs

Surface conditioning discs

Surface conditioning discs are generally used to reduce process time. They do this by combining multiple grit sequences into one convenient step. This sort of disc is generally used for polishing, blending, finishing, and deburring a variety of different types of metal. Some of the standout features of this kind of disc include minimized loading and unloading times, a dramatic reduction in heat build-up, reduced occurrence of frayed disc edges and grain shedding, as well as an extended usage life when compared to other types of sanding discs.

Shop Surface Conditioning Discs

No matter the job, our sanding discs can help you get it done. If you need assistance with selecting the right product for the job, feel free to call (800-816-3824), email, or chat with one of our experts today.

Abrasive Materials

Just like most other abrasives, sanding discs have a variety of different abrasive materials to choose from. The abrasive materials are the grains embedded in the disc that do the actual grinding. The different abrasive grains have varying properties that each have their pros and cons. The most common abrasive materials used in sanding discs include aluminum oxide, zirconia alumina, ceramic, and silicon carbide.

Aluminum Oxide:

Aluminum oxide is the most used material for most abrasive products, including sanding discs. This grain is suitable for sanding and grinding a variety of materials such as wood, most metals, and plastics. It is affordable, versatile, and has good durability. However, it may not be as effective for harder materials such as stainless steel.

Example - 2" Aluminum Oxide Die Grinder Sanding Discs

Zirconia Alumina:

Zirconia alumina, aka “Zirc”, is tougher than aluminum oxide and is used for sanding harder materials such as stainless steel, cast iron, and titanium. It has a longer lifespan and is more heat-resistant than aluminum oxide, making it ideal for heavy-duty grinding and sanding applications. Zirconia is also a great choice for high-pressured grinding and machining applications.

Example - 4-1/2" Curved Flap Disc


Ceramic abrasive material is designed to handle extremely tough sanding applications. It is ideal for grinding hard metals, such as steel and titanium, ferrous metals, and carbon steel. It is extremely durable, self-sharpening (friable), and resistant to heat, making it a good choice for high-speed grinding.

Example - 4-1/2" Ceramic Resin Fiber Sanding Discs


Diamond abrasives are the most durable and longest lasting abrasive materials. Diamonds are the hardest naturally occurring substances, making them capable of grinding and sanding extremely hard materials such as concrete, stone, and glass. However, diamonds are obviously very expensive, making these the most expensive abrasive material.

Silicon Carbide:

This abrasive material is razor sharp and ranked just slightly below diamonds on the hardness scale. Like ceramic, silicon carbide is also friable/self-sharpening, giving it the ability to have faster removal rates than other abrasives. It is best suited for sanding non-ferrous metals such as brass, copper, and titanium. It is also suitable for grinding glass, plastics, and refinishing hardwood floors. It is known for its aggressive cutting action and excellent finish. However, it is not as durable as other abrasive materials and may wear out quickly.

Example - 5" Silicon Carbide Sanding Disc


Non-woven sanding discs are a bit different than the coated abrasives mentioned above. These discs are constructed with a nylon-webbing, usually impregnated with abrasive grains. They are less abrasive than coated abrasives, making them ideal for finishing surfaces. 

Example - 4-1/2" Paint Stripping Wheel

Additional Resources

Choose The Best Sanding Discs for Different Applications

Now that you know more than you ever thought you needed to know about sanding discs, you just need to ask yourself the following questions to determine which disc you should use.

Main Questions to Ask Yourself When Choosing a Sanding Disc

1. What Tool Will I Attach the Disc To?

Different tools require specific types of sanding discs. First you’ll want to narrow down the types of sanding discs you’d need based on the tools you have available or that you plan to use.

  • Angle Grinder: Look for discs with a robust backing that can handle high speeds, such as fiber discs or flap discs.
  • Die Grinder: Smaller, more flexible discs like quick-change discs are ideal for the precision work die grinders are known for.
  • Orbital Sander: Hook and loop sanding discs are commonly used for their ease of attachment and detachment, suitable for repetitive tasks.
  • Rotary Tool: While similar to die grinders in handling detailed tasks, rotary tools are more versatile in the hobby and crafting space, requiring specific smaller diameter discs and various attachments like sanding bands, discs, and brushes for detailed and intricate work.
  • Stationary Disc Sander: Primarily used for rapid material removal and smoothing of large surfaces. These will require larger, stationary-specific discs, like a 7 inch PSA sanding disc, that are mounted onto a fixed plate. Ideal for shaping wood, smoothing edges, and other tasks where the workpiece is brought to the tool.

2. Do I Need to Use a Specific Attachment for My Sander/Grinder?

The attachment method can influence the ease of use and the efficiency of your sanding tasks.

  • Hook and Loop: Uses a Velcro-like (hook and loop) backing to make swapping discs easy. Ideal for tasks requiring multiple grits. Best for orbital sanders and dual-action sanders.
  • PSA (Pressure Sensitive Adhesive): Provides a firm attachment for tasks that require more pressure or for stationary sanders. Once adhered, they're less likely to shift during use but are not reusable like hook and loop.
  • Backing Plate: Backing plates/pads are necessary for certain types of grinders, ensuring stability and support for fiber discs and PSA discs.
  • Quick Change Discs: These discs use a unique roll on disc/ attachment, commonly known as 3M™ Roloc™ fastening system, that allows for rapid and easy swapping without the need for additional tools. The attachment uses an easy twist-on and twist-off motion, making them highly convenient for jobs requiring multiple grit changes or disc types within a short period. They are particularly popular with die grinders and some types of angle grinders, offering a secure fit that minimizes disc slippage during operation.
  • Threaded Attachment: Some sanding discs, like flap discs, easily attach to a grinder with a threaded attachment that you directly screw onto the grinder's spindle. This doesn’t require any additional tools or backing plates for attachment.

3. What am I Sanding or Grinding?

Material compatibility is key to selecting an abrasive grain that will effectively accomplish your task without causing damage.

  • Metal: The type of metal you're working with dictates the abrasive grain choice.
    • Aluminum Oxide: A great option for general metalworking, including ferrous and non-ferrous metals. Its durability and cutting ability make it a versatile choice.
    • Zirconia: Best suited for steel and stainless steel, zirc grains are durable and offer a good balance between material removal and longevity.
    • Ceramic: Recommended for harder metals, including stainless steel and high-carbon steels. Ceramic is also great for heat sensitive metals.
    • Silicon Carbide: Though less common for metal, silicon carbide can be used for polishing or when working with non-ferrous metals.
  • Wood: Silicon carbide or aluminum oxide work well, with silicon carbide being preferred for finishing tasks due to its finer grit options. Silicon carbide can often be used for wet sanding, depending on the backing material of the abrasive.
  • Paint Removal: Silicon carbide or ceramic discs are effective, as they can handle the removal of tougher layers without clogging too quickly. Aluminum oxide is also a useful option for a budget-friendly abrasive. Specific paint removal discs like the Black Hawk Abrasives Easy Strip Discs can remove paint without removing as much underlying surface material.
  • Composite Materials: Grinding composite materials like fiberglass or carbon fiber requires discs that can handle the tough fibers without getting clogged. Film backed sanding discs, or discs with silicon carbide or that are diamond-coated are often recommended for their ability to cut through these materials efficiently while minimizing heat buildup, which can damage the composite material.
  • Plastics and Acrylics: These materials are prone to melting or clogging the abrasive surface. Using a disc with an open coat and lower grit, along with a cool grinding technique (e.g., using low speeds and avoiding prolonged contact in one area), helps prevent heat buildup. Aluminum oxide discs are typically suitable for these materials, offering a good balance between abrasiveness and heat management.

4. What’s My End Goal?

Your project's end goal—whether it's material removal, surface preparation, or polishing—determines the grit and type of disc needed.

  • Aggressive Material Removal: Coarse grits (below 60) and discs like fiber discs are recommended for their cutting power and durability.
  • Paint Removal: Medium grits (80 to 120) on flap discs or stripping discs designed to remove paint without damaging the underlying surface.
  • Polishing: Higher grits (above 320) and finer discs, such as finishing discs or buffing pads, are used for achieving a smooth finish.
  • Prepping Paint for Wood: Medium to fine grits (100 to 220) are best for preparing wood surfaces for painting, ensuring smoothness without over-sanding.

Example Scenarios

Choosing the right sanding disc can be overwhelming with so many options to choose from. To simplify the process, you can try answering these scenario-based questions to pinpoint the ideal disc for your project:

Scenario 1: Refinishing a Vintage Metal Table

Angle grinder with a threaded attachment featuring a zirconia flap disc and a paint stripping disc, ideal for refinishing a vintage metal table by removing rust and old paint before polishing

  • Tool: Angle Grinder
  • Attachment: Threaded Attachment
  • Material: Metal (rusty and painted)
  • End Goal: Paint Removal and Polishing

Recommendation: Start with a paint stripping disc for paint and rust removal, followed by a zirconia flap disc for smoothing the surface. Finish with a high grit finishing disc or buffing pad for polishing.

Scenario 2: Restoring a Fiberglass Boat Hull

Orbital sander equipped with a green film-backed sanding disc and a gold stearate sanding disc, designed for restoring fiberglass boat hulls, showcasing medium to fine grit options for surface cleaning and prep work before repainting.

  • Tool: Orbital Sander
  • Attachment: Hook and Loop
  • Material: Composite Materials (Fiberglass)
  • End Goal: Surface Cleaning and Preparation for Repainting

Recommendation: Opt for gold stearate or film backed discs to handle the tough fiberglass without clogging. Start with a medium grit for cleaning and smoothing the hull, then move to a finer grit to prepare the surface for repainting.

Scenario 3: Building and Finishing a Hardwood Tabletop

Random Orbital Sander with vacuum dust collection system connected, shown with a gold aluminum oxide sanding disc with holes, perfect for efficient hardwood tabletop finishing and preparation for painting

  • Tool: Random Orbital Sander (preferably with dust collection)
  • Attachment: PSA
  • Material: Hard Wood
  • End Goal: Aggressive Material Removal and Prepping Paint for Wood

Recommendation: Begin with coarse-grit aluminum oxide discs for rapid material removal and shaping. Progress to medium and then fine-grit discs to smooth the wood surface thoroughly before applying any finish or paint. If your sander has a dust collection system installed, gold sanding discs with holes will make cleanup much easier and get a better sanding result faster. 

Scenario 4: Weld Prep on Steel

Skilled welder preparing steel for welding using an angle grinder equipped with a T29 zirconia flap disc, providing efficient weld prep by smoothing out steel surface imperfections

  • Tool: Angle Grinder
  • Attachment: Flap Disc with Threaded Attachment
  • Material: Metal (Steel)
  • End Goal: Preparing Steel Surfaces for Welding

Recommendation: Zirconia flap discs are highly recommended for weld prep on steel, offering durability and the ability to quickly smooth out imperfections without removing too much material. Start with a medium grit to clean and prep the surface, ensuring optimal weld quality.

Scenario 5: Autobody Paint Removal

Car trunk with partially removed paint showcasing the effectiveness of autobody paint removal using an orbital sander with hook and loop attachment, strip disc, and green film sanding disc options for a smooth finish before repainting

  • Tool: Orbital Sander
  • Attachment: Hook and Loop
  • Material: Paint on Metal (Car Body)
  • End Goal: Removing Old Paint for Repainting

Recommendation: Strip discs and wet/dry silicon carbide sanding discs are effective for autobody paint removal. For cars with Bondo or autobody filler, green film or gold stearate sanding discs are ideal. Begin with a coarse grit for rapid paint stripping and switch to a finer grit to smooth the surface without damaging the metal. The flexibility of hook and loop attachment allows for quick grit changes, adapting to varying surface conditions.

Tips When Using Sanding Disc

  • Different sanding discs require different backing pads. It's important that you use the backing pad that’s compatible with both the machine and the sanding disc you are using.
  • Angle grinders and other tools come with guards for a reason. Make sure to always reinstall the guard before turning on your equipment.
  • Whenever using sanding discs, it is always important to wear appropriate PPE (Personal Protective Equipment).
  • Sanding and grinding release very small particles into the air, some that can be extremely dangerous when inhaled. Make sure to wear a respirator and have good ventilation. 
  • Let the disc do the work and don't apply too much pressure
  • Sanding discs, attachments like backing pads and the actual tool are all rated for different RPMs. It's important to verify all of your equipment works within the same RPM ranges.
  • To get the most out of your sanding disc, ensure it is properly cleaned after each use. This can be done with a sanding disc cleaning stick.

Speak with an Expert

Still need help selecting the right sanding discs? Speak with one of our experts about what you’re trying to accomplish, and we’ll recommend the best product for the job. TOLL FREE 800-816-3824