Question about Tapping threads

[bakerboy4679]

When tapping the standard 1/4- 27 NPT threads(Gauge size), what size drill bit do you use?

I know it has to be slightly smaller than the tap, but just curious.

[Edwin]

http://www.kramerusa.com/DrillTapChart.htm

[bakerboy4679]

Oops, my bad, I put 1/4" instead of 1/8" NPT threading, is that correct threading for a gauge? I thought it was 1/4... right??

[Edwin]

1/8-27 npt (National Pipe Thread)

[bakerboy4679]

Gotcha.. thanks.