Weiler 30821 Non-Woven Type 29 Zirconium Flap Disc - 36 Grit - Very Coarse - 4" Diameter - 5/8" Center Hole

Weiler non-woven Type 29 flap disc uses zirconium as the abrasive material and has a diameter of 4 in. Since this product is non-woven, grade is generally used to describe the abrasiveness; with the 30821 having a very coarse grade. Weiler incorporates this zirconium material into the flap disc forming a grit of 36. All abrasive products that rotate or spin, such as the ones in this category, have a maximum speed at which you can run them. This Weiler flap disc can be run at a maximum speed of 15000 RPMs. The Weiler flap disc uses aluminum for the backing plate.
Specifications:

Abrasive Type: Non-Woven

Flap Disc Type: Type 29

Specification parameters description:
Abrasive Material:
Values: A/O Aluminum Oxide AO A/Z Alumina Zirconia AZ Alumina Zirconia Alumina zirconia is very dense and can be used under high temperatures for heavy-duty stock removal, wood planing, and grinding of fiberglass and plastics. The abrasive grain is designed to fracture during use so that it maintains sharpness. Aluminum Oxide Aluminum oxide is an artificial abrasive suited for general purpose stock removal and finishing. It is the mostly commonly used abrasive and can be used for most steels and ferrous alloys. Aluminum oxide is slightly softer but tougher than silicon carbide. Aluminum Oxide/Ceramic PSG Ceramic Ceramic is used for aggressive cutting and grinding of stainless steel, titanium, and metal alloys. The abrasive grain is designed to fracture during use so that it maintains sharpness. Ceramic Alumina Ceramic/Alumina Zirconia Ceramic Aluminum Oxide Ceramic Precision-Shaped Grain Diamond Diamond can be either natural or manufactured and is one of the hardest abrasive materials. It is commonly used for grinding and polishing stone and very hard steels, and for sharpening other cutting tools. S/C Silicon Carbide SC Silicon Carbide Silicon carbide is a manufactured material that is extremely hard but brittle. It is commonly used for fast cutting under light pressure, particularly on cast iron, nonferrous metals, and materials such as glass and plastic. Zirconia Zirconium
Grade:
Grade is a measurement of the size of abrasive particles embedded in coated abrasives. It is a more general measurement of the level of precision, and corresponds roughly to grit. A smaller grit number means larger particles and a coarser grade, while high number grits are used for finer work.
Maximum RPM:
The maximum rotations per minute (RPM) a product is designed to be used at should be respected for the sake of safety and use life. Maximum RPM is provided for all product listings where applicable and is often printed on the item in the case of discs and wheels. Operating a wheel above its maximum recommended speed can cause a wheel to crack or even shatter.
Grit:
Grit is a measurement of the size of abrasive particles embedded in coated abrasives. The most common standards for grit size are the United States CAMI (Coated Abrasive Manufacturers Institute) and the European FEPA (Federation of European Producers of Abrasives). A smaller grit number means larger particles and a coarser grade, while high number grits are used for finer work. Grit is generally a unitless measure but is sometimes measured in microns.
Backing Plate Material:
Flap discs are three dimensional discs consisting of abrasive flaps glued to a backing plate. Fiberglass is the most commonly used backing and is very strong and durable. Reinforced nylon plastic is becoming more common and has the advantage that the backing can be trimmed away to increase usage of the abrasive materials. Non-reinforced nylon backing is only semi-rigid for conformability to work surfaces. Discs can also have a phenolic resin backing, which wears uniformly with the flaps. Metal backings are the safest to use and also the most aggressive, but are the most expensive. The most common metal backing is aluminum, though stamped steel is also used.