Machining titanium and stainless steel jewelry

Step 5 Drill the bar

Drill a hole through the bar. This should be the right size for the tap we'll use to cut the threads. I'm using a 1-72 tap, so it's a #53 drill bit which is 0.059 inch or 1.511 mm. As an interesting trivia point, number drill bits are measured using American Wire Gauge (AWG), which is completely different from the B&S wire gauge for piercing sizes.

I drill the hole all the way through the bar, drilling half the depth from each end. I think this lets me do a better job of cleaning out cutting oil, chips, and general muck from the threads. Make sure to use some kind of lubricant on the drill bit and back it out frequently to clear out metal shavings.