3M Hookit Disc Pad - Hook & Loop Attachment - 5 inch diameter. 3M Hookit disc pad has a diameter of 5 in. The hook & loop 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 3M part is 3/8 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 3M disc pad can be run at a maximum speed of 12,000 RPMs.