Did you know this use for a drill bit? It's so simple you'll kick yourself when you see it! Using a drill bit as a physical stop and guide is a really accurate way to measure things.
If you buy high quality drill bits, they're pretty spot on for size but even these cheap drill bits I have are accurate to within at least 0.1 of 1mm. That's accurate enough for me!
A great use for drill bits is to use them to set the depth of router bits! All you need is 2 drill bits that are the same size (I used 6mm bits) and a flat surface.
First, place the 2 drill bits on the flat surface slightly spaced apart. Then loosen the base of the router so you can raise and lower the bit.
Place the base of the router on top of the 2 drill bits.
Now lower the router bit until it touches the flat surface.
Then you can lock it in place and be confident the router bit is protruding 6mm from its base. The same depth as the drill bits!
You can do the same at the router table... just upside down! Again you need 2 drill bits that are the same size and a flat surface.
First, lower the router bit so its lower than the drill bits thickness. Then place the 2 drill bits either side of the router bit.
Place the flat surface on top of the drill bits and gently rock it back and forth.
As you rock it back and forth slowly raise the router bit.
When you hear the router bit start to catch on the surface you know you're at the right position. The router bit will be raised to the same height as the drill bits!
Another great use for drill bits is to set the distance of fences. I'll demonstrate on a Bandsaw but it works the same on a Table Saw or any other tool that uses a fence!
First, place the drill bit (12mm bit in my case) against the blade. Then bring the fence up to it until it touches the drill bit. Then lock the fence in place. Be careful though, fences can move when you lock them in place so move the drill bit back and forth to make sure it isnt too tight or too lose. Make any adjustments to the fence that's needed until the bit moves smoothly without catching and without any play. That way you know the fence is exactly the distance of the drill bit away from the blade.
That was 12mm in my case! Keep this tip in mind next time you need to set up tool and equipment accurately. Drill bits can be used for more than just drilling holes!