... Size:4",7". 3. Used for grinding and polishing steel. 4. Patent NO:ZL200820152959.7 Specifications of flexible flap ... .2. Size:4" (100*16mm). 3. Number of page :45page.4. Matrix Angle:T27 (0-15°).Flexible flap ... /Plastic It used for Regular steel.Stainless steel,Cast iron,ordinary carbon steel.Alloy steel,Non-ferrous metal and Timber ... !... Flexible flap disc 4" iron back 45 page KBLD zirconium