What are these ?

[taylor1]

Can someone please tell me what these are used for and what the numbers represent 

[Joe Frickin' Friday]

Stepped drill bits for countersunk wood screws.  Some wood screws have un unthreaded shank that's larger in diameter than the thread root:

 

 

 

 

On those drill bits, the smallest diameter drills the pilot for the threaded part, the next largest diameter drills the clearance for the unthreaded shank, and the angled part drills the countersink for the screwhead - all with a single bit and a single machining operation.

 

Another version here:

https://www.rockler.com/4-piece-wood-screw-countersink-pilot-hole-drill-bit-set

 

 

[lkraus]

Combo drill/countersinks for wood screws. They will make holes of the proper diameters for the thread, shaft, and head. The top markings indicate the screw size(s), the bottom indicates the length of the screw.

[taylor1]

Ah Ha  Thank You

[BamaJohn]

I was thinking they were depth markers for a proper pour of scotch  (or bourbon)!

[taylor1]

I like it . A multi tool. Will give it a try tonight !

[bhulse]

Take note of the three perpendicular slots in the shank.  There were spring clip depth gauges to limit the depth of the head (counter sunk) below the surface of the piece being bored!  Had to be real careful and not run up on them hard at the end of the stroke cause they often broke!