4 x 21 Sanding Belts

Premium Quality 4 X 21 Inch Sanding Belts

Quality 4 x 21 inch sanding belts can be hard to find. Many manufacturers no longer offer belts in this size, but Red Label Abrasives does. We manufacture premium quality, industrial grade 4 x 21 inch sanding belts and ship them directly to your door. Keep your sanding projects moving with some of the best 4 x 21 sanding belts on the market. 

Types Of 4” x 21” Sanding Belts We Offer

Red Label Abrasives offers two different types of sanding belts in a 4 x 21 inch size. A brief description of each type of belt can be found below. You can also speak with a Red Label abrasive technician for help determining which type of belt would be best for you. 

• Open coat aluminum oxide: Open coat aluminum oxide sanding belts are great multipurpose sanding belts. They are both economical and versatile. In fact, aluminum oxide is considered the workhorse of abrasive grains and it’s the most popular abrasive grain. Open coat aluminum oxide works really well for sanding soft woods, but it can also be used for sanding hardwoods, plastic, composites, metal, and many other materials.
• Closed coat aluminum oxide: Closed coat aluminum oxide uses the same aluminum oxide grains found in open coat aluminum oxide. The difference between the two types of belts is the coating. All of the belt's surface is covered with abrasive grains for closed coat belts. This coating decreases air flow between the grains, but it increases the cut rate for the belt. Closed coat aluminum oxide is designed for harder materials that need a more aggressive cut like metal and hardwood.  
• Silicon carbide: Silicon carbide is a specialty abrasive grain that works well with very specific applications. Silicon carbide sanding belts are primarily used to sand marble, garnet, and glass. 
• Zirconia: Zirconia was the toughest abrasive grain on the market before ceramic. Zirconia now strikes a nice balance between longevity and affordability. Zirconia sanding belts cost less than ceramic sanding belts and lasts two to three times longer than aluminum oxide sanding belts. Zirconia sanding belts work best on harder materials like metals and hardwoods. 
• Ceramic: Ceramic is an ultra premium abrasive grain. It costs more than zirconia and aluminum oxide, but it also lasts longer than both. Makers often save money long-term by purchasing ceramic sanding belts, because they don’t have to order replacement belts as often. Ceramic is one of the strongest abrasive grains on the market. It provides an aggressive cut and can save you time on sanding. Ceramic sanding belts work well for harder materials like hardwoods and metals. 
• Flexible sanding belts: Flexible sanding belts are able to flex or curve with a sanding surface - as the name implies. Flexible sanding belts are great for sanding circular edges, angles, and round surfaces. The belt will mold to the surface to provide a smooth finish throughout. Our flexible sanding belts are available with ceramic grains for grits up to 400 and aluminum oxide grains for grits up to 7,000. 

Why Purchase 4 x 21 Inch Sanding Belts From Red Label Abrasives? 

Red Label Abrasives is well-known as an industry leader for sanding belt manufacturing. Our proprietary belt joints are strong and ensure that your belt will have a long lifespan without snapping or breaking. Our 4 x 21 inch sanding belts are produced to be industrial grade. They are some of the most effective and longest-lasting belts on the market. They are also made-to-order or limited stock, which ensures that only fresh belts are shipped to your door. 

As the manufacturer, we’re able to offer very competitive pricing and free shipping on all orders (something many of our competitors do not offer). We’re so confident you’ll like our belts that we even provide a 90 day 100% money back guarantee. 

Affordable prices and unbeatable products aren’t the only benefits you get when you order 4” x 21” sanding belts from Red Label Abrasives. We’re able to deliver an unrivaled level of customer support as a family-owned business. You’ll never have an issue speaking with an abrasive technician about product questions or order details when you contact us during normal business hours (Monday-Friday: 8am - 4pm ET).

Speak With An Abrasive Technician