What size drill bit do you use for a 1/4-20 tap?

13/64″

To Tap This Size Screw Or Bolt:	Use This Drill Bit:	(Closest Fractional:)
14-20 NS	#10	–
1/4-20 NC	#7	13/64″
14-24 NS	#7	–
6mm-1.00mm	5.2mm	–

What size drill bit do you use for a 1/4 pipe tap?

Tap size	Threads per inch	Drill size w/ taper pipe reamer
1/16	27	15/64
1/8	27	21/64
1/4	18	27/64
3/8	18	9/16

What is the drill size before tapping for ¼ 20 Unc?

Tap, Drill, & Clearance Hole Sizes Chart

Thread Size	Tap-Drill Sizes	Clearance Holes
Size	Non-Struct (1/64 OS)
1/4-20-UNC	No. 7	17/64
1/4-28-UNF	No. 3	17/64
5/16-18-UNC	‘F’	21/64

What is number 7 drill bit?

A number 7 drill bit is 0

What is an R drill bit?

Drill bit “R” is .339″ in diameter. Hope that helps. danc46 , 09-14-2007 03:39 PM. Registered User. It’s smaller than the Q drill bit and larger than the S drill bit.

What is the tapping drill size for 1 ⁄ 4 BSW thread?

British Standard Pipe Parallel or Taper BSP or BSPT

Nominal Size (inches)	T P I	Tapping Drill Size
1/4	19	11.2mm
7/16″
3/8	19	14.75mm
37/64″

What is a 15 64 drill bit?

Drill Bit Hole Diameters
Metric Size	Fractional Size
6 mm	.2362	15/64
7 mm	.2756	1/4
8 mm	.3150	17/64