Steam gauge mounting screws...

[Michael Burbidge]

I bought a jig from Avery Tools for drilling the mounting screws holes for my steam gauges. The instructions that came with the jig said to use a #16 drill bit. What size screw goes in a #16 hole? It is not an 8 nor a 6.

Michael-

 

[az_gila]

Tolerances - aka slop...

I bought a jig from Avery Tools for drilling the mounting screws holes for my steam gauges. The instructions that came with the jig said to use a #16 drill bit. What size screw goes in a #16 hole? It is not an 8 nor a 6.

Michael-

It's just a bit oversize to allow for tolerances in your manual (non-CNC) drilling.

Typically it is a 0.170 hole (#18) but a 0.177 is close enough for the same effect...

http://www.rst-engr.com/rst/jimsdata/Insthol3.pdf

http://www.craggyaero.com/Drawings/Instrument Hole Templates.pdf