Thread - Pilot Drill Charts

[Jacques Reed]

Good Day All,

Just a slight diversion from topic but which many may find interesting.

After posting a picture of my numbered drill set I remembered that Ford carburetor jet sizes are given in number drill sizes. I know jet sizes have been covered before on MLU, but I thought I would see if any of my number drills matched an old Ford Holley carburetor jet I kept.
Many are missing from the set but #54 was there and a quick micrometer check confirmed it. The jet is numbered 054 which is the drill size.
I see on another MLU post the Ford CMP truck jet size was 050 except for the Workshop truck which was 053. Some American Flathead Ford sites specify 051 as standard, probably for cars. Quite a few sizes are available and it is a separate subject in its own right, but I thought others may find this interesting especially those new to the old Ford engines or just old engines in general.

So numbered drills are still being used in manufacturing, at least for replacement carby jets.

Cheers,