Eraser Wheel has serrations for improved cooling effect air flow.
Dynabrade surface grinding wheel has a diameter of 4 in. The quick change attachment allows for easy mounting to the tool or pad. In addition to the other aspects of these parts, another important component of these is the thickness. This Dynabrade part is 1 1/4 in thick. 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 Dynabrade surface grinding wheel can be run at a maximum speed of 4000 RPMs.

Dynabrade 11254 Contact Arm Ass'y, 4-3/4" Dia. x 1/2" W
Dynabrade 11477 Dynabelter Abrasive Belt Tool, Heavy-Duty
Dynabrade 11475 Dynabelter Abrasive Belt Tool, Standard Duty
Dynabrade 14000 Dynafile Abrasive Belt Tool
Dynabrade 78575 5" Dia. x 1/4"-20 Female Center Thread, 60 Grit, A/O, 3-Ply, J-DynaCut Eyelet Star, 50/pack
Dynabrade Nitro Series DGS31 .3hp, 25,000 RPM, Straight-Line Die Grinder, 1/4 Collet
Dynabrade 95842 Dynabrade Air Lube 10W/NR, 1 Pint 
