Ansi Screw Clearance Holes

Machi Machi ne Screw and Drill Size Chart Chart (Englis h)

Screw Designation Number Diameter Pitch Tap Si Size or dia. (inch) (threads/inch) #0 #1 #1 #2 #2 #3 #3 #4 #4 #4 #5 #5 #6 #6 #8 #8 #10 #10 #12 #12 #14 #14 1/4 1/4 5/16 5/16 3/8 3/8 7/16 7/16 1/2 1/2

0.06 0.073 0.073 0.086 0.086 0.099 0.099 0.112 0.112 0.112 0.125 0.125 0.138 0.138 0.164 0.164 0.19 0.19 0.216 0.216 0.242 0.242 0.25 0.25 0.3125 0.3125 0.375 0.375 0.4375 0.4375 0.5 0.5

80 64 72 56 64 48 56 36 40 48 40 44 32 40 32 36 24 32 24 28 20 24 20 28 18 24 16 24 14 20 13 20

0-80 1-64 1-72 2-56 2-64 3-48 3-56 4-36 4-40 4-48 5-40 5-44 6-32 6-40 8-32 8-36 10-24 10-32 12-24 12-28 14-20 14-24 1/4 - 20 1/4 - 28 3/16 -18 3/16 - 24 3/8 -16 3/8 - 24 7/16 - 14 7/16 - 20 1/2 - 13 1/2 - 20

1/4 -

20 -

UNC

x 3/4"

Nominal Dia. (inch)

Threads per per inch inch

Thr Thread ead Ser Serie ies s

Length of thread

UNC - Unified Coarse UNF - Unified Fine

3/64 53 53 50 50 47 45 44 43 42 38 37 36 33 29 29 25 21 16 14 10 7 7 3 F I 5/16 Q U 25/64 27/64 29/64

Clearance Hole Drills Close Fit Loose Fit Drill Diameter Drill Diameter   Size (inch) Size (inch)

0.0469 52 0.0635 0.0595 48 0.076 0.0595 48 0.076 0.07 43 0.089 0.07 43 0.089 0.0785 37 0.104 0.082 37 0.104 0.086 32 0.116 0.089 32 0.116 0.0935 32 0.116 0.1015 30 0.1285 0.104 30 0.1285 0.1065 27 0.144 0.113 27 0.144 0.136 18 0.1695 0.136 18 0.1695 0.1495 9 0.196 0.159 9 0.196 0.177 2 0.221 0.182 2 0.221 0.1935 D 0.246 0.201 D 0.246 0.201 F 0.257 0.213 F 0.257 0.257 P 0.323 0.272 P 0.323 0.3125 W 0.386 0.332 W 0.386 0.368 29/64 0. 0 .4531 0.3906 29/64 0.4531 0.4219 33/64 0.5156 0.4531 33/64 0.5156  For 75% thread engagement  Coarse thread (UNC) used for aluminum, brass, cast iron, plastic; Fine thread (UNF) for steel, titanium

Typical Machine Screw Designatio Designatio n

(or screw #)

Tap Drill Size Drill Diameter Size (inch)

50 46 46 41 41 35 35 30 30 30 29 29 25 25 16 16 7 7 1 1 F F H H Q Q X X 15/32 15/32 17/32 17/32

0.07 0.081 0.081 0.096 0.096 0.11 0.11 0.1285 0.1285 0.1285 0.136 0.136 0.1495 0.1495 0.177 0.177 0.201 0.201 0.228 0.228 0.257 0.257 0.266 0.266 0.332 0.332 0.397 0.397 0.4687 0.4687 0.5312 0.5312