Carbide Tools: Solid Like a Rock - carbide insert lathe tools

It happens to everyone. You open a drawer only to find scattered drill bits. They are similar enough that identifying one you need almost seems impossible. And even if they are regularly spaced inside a package, choosing the right one can be daunting. Even professionals get confused at times. Drill bits come in fractional sizes, with gradations as small as 1/64th, reports Home Repair Geek. But, there are ways to size and select a drill bit through markings and testing.

Calipers are small hand-held tools. They look like a small, flat handle with two jaws at the top. The bottom jaw slides up and down. To size a screw, place the body of the screw (not the head) between the jaws and push the jaws shut with your fingers. You can pick up a pair of calipers at any home supply or tool store. Keep them handy for screw size identification and you can't go wrong.

When you purchase a new set of bits, or identify your old ones with calipers, drill a series of holes through a thin, flat piece of metal. Mark each hole with the drill bit's size. If you get confused about what drill bit you've picked up, check the fit by inserting the bit into one of the holes.

Typical drill bits have markings somewhere on the shank above the threads. It's small, but it usually has the drill-bit diameter stamped into the metal; the number is written in fractions. For example, the markings may read: 1/4-inch, 3/6-inch or 25/32. Some graduate in 16ths, some graduate in 32nds, some even graduate in 64ths. The diameter of a screw or bolt is measured from the outer thread on one side to the other side's outer thread, according to Fastener Superstore's Fastener Guide.