From a woodworking/finishing aspect, both the 3/16″ and 3/32″ are good for sanding wood. In some instances, you may need to use a lighter touch with the 3/16″ orbital sander because it’s more aggressive than the 3/32″ random orbital sander and will remove material at a faster rate. Applications such as outside edge details or following steps in moldings on a line are much easier to tackle with the tight 3/32” random orbital sander.