Fibre Discs P24 to P36 Grit Velcro Discs 180mm dia x 22mm. (Priced Per 250 Discs). (2 Weeks Lead Time). (Choose a Grade from the drop down list). The Fiber discs are durable and flexible, making them very suitable for sanding difficult surfaces. Fiber has firm dust binding properties, which is needed when removing lacquer and rust or when sanding down welding seams. Fiber discs are coated with aluminium oxide.