What are the different types of backings used in coated abrasives?

1. Cloth – Cloth backings come in various weights, from Stiffest to the most Flexible – (Y, X, J, F)
   • “Y” Weight – This extremely heavy duty cloth is used for tough applications. It is usually made of Polyester for added strength & tear resistance.
   • “X” Weight – This heavy cloth, also called drills, is recommended for all ordinary machine sanding operations.
   • “J” Weight – This flexible, lightweight cloth, also called jeans, is used where more flexibility is needed, such as with contour sanding.
   • “F” Weight – This highly flexible, lightweight jeans cloth is used when extreme flexibility is desired.
2. Paper – Paper backings come in different paper weights, designated by letters, are available for different applications.
   • “A” Weight – This light touch 40# paper is primarily used in finishing operations where fine grits are required.
   • “C” Weight – This medium light 70# paper is used when some pliability and strength are required. It can be used in folded or flat areas and is ideal for cabinetwork. This backing is available in fine to medium grits.
   • “D” Weight – This medium heavy 90# paper is available in medium and coarse grits.
   • “E” Weight – This strong 130# paper is used for belts, discs, rolls and very coarse sheets.
   • “F” Weight – This 165# paper is used for narrow and wide belts, metal and crankshaft polishing rolls, and cabinet and furniture industries.
3. Fiber – Fiber is a hard, durable material with great mechanical strength. It is used exclusively to make resin fiber discs.
4. Film – Used most often for DA sanding discs for orbital sanders. The film backing is more durable than paper & can be used wet or dry.