Strange Drillbits

So I grabbed a lot of strange step drill bits at the local used tool store, and am trying to figure out their original purpose. Google has been no help, so here is all I know: They seem to be of two groups, all appear the same, but the part numbers are of the form KCT-xxxx or CTA-xxx All are steel with, some are marked 'W&S', either monogram, or simple printing. Scans may make more sense than words

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numbers on the drills are, from top to bottom:

  • KCT-90 w&s monogram, "u" (the quotes are on the drill) and the Cincinatti symbol
  • KCT-1129 / 3740 W&S
  • KCT-1129 / 3740 W&S
(same as 2nd)
  • CTA-1768 / 1/2(inverted)



Reply to
Joe Sixpack
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They are D bit reamers. Designed to drill and ream to close tolerances.

Reply to
Dave Baker

In the shop I worked in about the time Bush and Kerry were doing their Viet Nam era military stuff those combination drill/reamers were referred to by the guys as "Dreamers".

One of the "blocks for pounding things on" that on my home shop bench was a mismachined "trunion block" intended for one of those GE "Gatling Guns" fired from the US choppers in Nam.

It's a block of 4140 about 6x4x1-1/2 inches with short cylindrical spuds turned onto the small ends.

We "subbed" several different parts for those guns in that shop.

Thanks for the mammaries...

Reply to
Jeff Wisnia

Joe Sixpack

wrt id for:

Don't know. Can't see any cutting edges from the scans. Looks like offset centers. But some function (whether cutting or line-up) that has the business end offset from the main shank. FM

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