Prevent over-drilling

Tip #3: Stop collars provide the ultimate solution

For a few dollars' investment, stop collars give you a can't-fail means of repeatedly drilling to a predetermined depth. Slide the collar onto the bit, then tighten the setscrew(s) securely against the outside surfaces of the flutes (not inside the flutes or on their cutting edges). Be warned: Steel stop collars, although priced attractively, can mar your wood surface. Instead, try SlipStop collars, shown in photo. A nylon boot allows the stainless-steel collar to spin within it, preventing wood damage.