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

Published by Charlie Davidson on

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

Categories: Users' questions