[Amps] RE : amp hardware

[gdaught6 at stanford.edu]

On 11 Apr 2007 at 8:23, Ian White GM3SEK wrote:

< snip, snip >

> Drill exactly the right size of pilot hole (not too big, not too 
> small)  

Which brought to mind a question that I've been dealing with for 
many, many years:  "What is the correct size pilot hole for self-
tapping sheet metal screws?"  I have always measured the screw at its 
narrowest body diameter (i.e. not at the pointy tip) using a vernier 
caliper with jaws that will fit to the bottom of the thread.  [An old 
machinist I knew always called it a "very near caliper" because the 
measurement obtained was "very near the correct dimension."]

Anyhow, is there a chart like the tap-drill sizes vs. screw sizes 
that I've been missing all of this time?

73,

George T. Daughters, K6GT