This unique jig drills through the corner of the hex, making it ideal for drilling nuts as well as bolts. Full adjustability allows use on virtually any hex-head fasteners up to 1 1/16" (27mm) hex: SAE, metric, even Whitworth! Requires a 1/16" Drill Bit (Part No. 3746), sold separately. Not for use on reduced-hex nuts such as MS21042 Jetnuts or plumbing tube nuts. The hex size must be 1/8" (3mm) larger than the thread size to avoid drilling through the threads.
Tech Tip: Drilling through the corner of the hex means drilling at an angle to the surface. Even with a drill jig, the sideways pressure will tend to make the drill bit push towards the corner of the hex. This results in a very shallow hole. In extreme cases, the bit may even just cut a groove in the corner of the hex. For best results use a drill press and advance the bit VERY SLOWLY.
To minimize skipping and push-out, start a shallow pilot hole perpendicular to the hex face using a 1/8" drill bit with a standard 60° point angle. The 1/16" bit should then drill into the angled face where the lip (face) of the larger bit has drilled. Center-punch to minimize drill walking.
For more details, see Chapter 4 of Carroll Smith's Prepare to Win, "Drilling Offset Holes."