Four years after I bought my Fein sander, the manufacturer is still advertising that its 636 triangular sander "eliminates hand sanding." This is not precisely true, but it comes awfully close. Fact is, this machine can sand all the way into a corner (such as a drawer bottom) without disfiguring adjacent surfaces (like the drawer sides). It can do this because the sanding head oscillates extremely rapidly (20,000 strokes per minute) through a very narrow range of movement (only 2°). Oscillating Action Unlike tools with a fundamentally rotary action, such as random-orbit sanders and disc grinders, the Fein's sanding action eliminates radial momentum, which typically drives the abrasive material into unintended surfaces. Instead of spinning a disc, the Fein has an
