[HiFi1972]

Somewhere, I've seen a type of ruler that has common diameters of holes used for jacks and that sort of thing, which tells you what size of bit to use. Can someone please put me on? Thanks!

 

[Uncle Erik]

I've seen those, too, but am not sure if they have a specific name.

I use calipers. I measure whatever it is that I want to install then pick the appropriate bit or scribe the hole to cut.

 

[NightOwl]

Drill Bit Gauge?

Drill Bit Gauge

 

[Rayko]

Quote:

Originally Posted by HiFi1972 /img/forum/go_quote.gif Somewhere, I've seen a type of ruler that has common diameters of holes used for jacks and that sort of thing, which tells you what size of bit to use. Can someone please put me on? Thanks!

Drill bit gauge:
Ace - Ace Tree: Tools: Power Tools: Drills & Screwdrivers: Drill Bits & Bit Sets: Drill Bit Indexes: Irwin® Drill Gauge (12092)

There's a chart here:
Drill bit sizes - Wikipedia, the free encyclopedia

 

[kuroguy]

go to any art supply and look for a circle template.