FAQ's

What is PSA?

PSA is Pressure Sensitive Adhesive.  It is the glue that is on the back of the sandpaper disc.  This glue attaches to the blue vinyl material on the bottom of the pad.

Why are there different sizes of hooks?

The size of the hook needs to be compatible with the loop on the abrasive disc.  As a general rule of thumb, a smaller hook works better with a dense loop and a larger hook works better with a sparse hook.  For example, the loop on the back of a coated disc (sandpaper) works best with smaller hooks.  The loop on the back of surface conditioning discs works better with larger hooks.

How do I determine the correct diameter?

The size of the pad needs to be the same size of the abrasive disc being used.  Please note back up pads are normally undersized by roughly 1/8” to allow a overhang.  This makes it easier for the operator to center the disc and peel it off after use.

What is the normal thread size?

There are basically two types of threads, male and female.  The standard male thread is 5/16 x 24.  This is common on most every dual action, random orbital tool (DA tools).  The standard female thread is 5/8 x11.  This is common on most every angle sander, grinder and polisher.  Please note that metric threads are becoming more common and are available on our products.

Do I need a firm or soft pad?

The durometer (hardness or softness of the foam) depends on the surface you are working on and the grit of the abrasive.  Normally, but not always, the more aggressive the grit, the firmer the pad.  That can also be said for the flatter the surface, the firmer the pad.