|Square "Wood Screws" (Using Brad or Standard Point Drill Bits)|
|Standard "Wood Screws" (Using Taper Point Drill Bits)|
Drill bit selection, for Square Drive screws and other fasteners, should take into consideration the material’s properties. When using harder materials, or “soft” screws, larger pilot holes are required.
The table (shown right) is a starting point- a quick technique is to hold a drill bit up to the shank of the screw. If you’re breaking screws, try enlarging the pilot hole-even 1/64" will make a difference. Nominally, the proper bit is the same size as the shank between the threads. In practice, use a slightly larger bit for hardwoods and a slightly smaller bit for softwoods. The root diameter of a Square Drive screw is smaller than that of a standard “wood screw;” pilot recommendations are also smaller.