Standard Drill Sizes

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Standard Drill Sizes
All Standard Drill Size Bushings Are indicated in Green

Drill	Decimal	Drill	Decimal	Drill	Decimal	Drill	Decimal	Drill	Decimal
80	.0135"	70	.0280"	60	.0400"	51	.0670"	3/32	.0938"
79	.0145"	69	.0292"	59	.0410"	50	.0700"	41	.0960"
1/64	.0156"	68	.0310"	58	.0420"	49	.0730"	40	.0980"
78	.0160"	1/32	.0313"	57	.0430"	48	.0760"	39	.0995"
77	.0180"	67	.0320"	56	.0465"	5/64	.0781"	38	.1015"
76	.0200"	66	.0330"	3/64	.0469"	47	.0785"	37	.1040"
75	.0210"	65	.0350"	55	.0520"	46	.0810"	36	.1065"
74	.0225"	64	.0360"	54	.0550"	45	.0820"	7/64	.1094"
73	.0240"	63	.0370"	53	.0595"	44	.0860"	35	.1100"
72	.0250"	62	.0380"	1/16	.0625"	43	.0890"	34	.1110"
71	.0260"	61	.0390"	52	.0635"	42	.0935"	33	.1130"

Drill

Decimal

Drill

Decimal

Drill

Decimal

Drill

Decimal

Drill

Decimal

.1160"

.1540"

.1820"

.2055"

.2500"

.1200"

5/32

.1562"

.1850"

.2090"

1/4

.2500"

1/8

.1250"

.1570"

3/16

.1875"

.2130"

.2570"

.1285"

.1590"

.1890"

7/32

.2188"

.2610"

.1360"

.1610"

.1910"

.2210"

17/64

.2656"

.1405"

.1660"

.1935"

.2280"

.2660"

9/64

.1406"

.1695"

.1960"

.2340"

.2720"

.1440"

11/64

.1719"

.1990"

15/64

.2344"

.2770"

.1470"

.1730"

.2010"

.2380"

.2810"

.1495"

.1770"

13/64

.2031"

.2420"

9/32

.2812"

.1520"

.1800"

.2040"

.2460"

.2900"

Drill

Decimal

Drill

Decimal

Drill

Decimal

Drill

Decimal

Drill

Decimal

.2950"

23/64

.3594"

29/64

.4531"

41/64

.6406"

53/64

.8281"

19/64

.2969"

.3680"

15/32

.4688"

21/32

.6562"

27/32

.8438"

.3020"

3/8

.3750"

31/64

.4844"

43/64

.6719"

55/64

.8594"

5/16

.3125"

.3770"

1/2

.5000"

11/16

.6875"

7/8

.8750"

.3160"

.3860"

33/64

.5156"

45/64

.7031"

57/64

.8906"

.3230"

25/64

.3906"

17/32

.5313"

23/32

.7188"

29/32

.9062"

21/64

.3281"

.3970"

35/64

.5469"

47/64

.7344"

59/64

.9219"

.3320"

.4040"

9/16

.5625"

3/4

.7500"

15/16

.9375"

.3390"

13/32

.4062"

37/64

.5781"

49/64

.7656"

61/64

.9531"

11/32

.3438"

.4130

19/32

.5938"

25/32

.7812"

31/32

.9688"

.3480"

27/64

.4219"

39/64

.6094"

51/64

.7969"

63/64

.9844"

.3580"

7/16

.4375"

5/8

.6250"

13/16

.8125"

1.000"

Thread Size/ Tap Drill Size
*Indicates Size of drill to be used before tapping

American Standard Thread ISO Metric Thread

Thread Size Tap Drill Size (in.)* Thread Size Tap Drill Size(mm)*

0-80 3/64 M1 x 0.25 0.75

1-64 53 M1.1 x 0.25 0.85

1-72 53 M1.2 x 0.25 0.95

2-56 51 M1.4 x 0.3 1.10

2-64 50 M1.6 x 0.35 1.25

3-48 5/64 M1.8 x 0.35 1.45

3-56 46 M2 x 0.4 1.60

4-40 43 M2.2 x 0.45 1.75

4-48 42 M2.5 x 0.45 2.05

5-40 39 M3 x 0.5 2.50

American Standard Thread		ISO Metric Thread
Thread Size	Tap Drill Size (in.)*	Thread Size	Tap Drill Size(mm)*
5-44	37	M3.5 x 0.6	2.90
6-32	36	M4 x 0.7	3.30
6-40	33	M4.5 x 0.75	3.70
8-32	29	M5 x 0.8	4.20
8-36	29	M6 x 1	5.00
10-24	25	M7 x 1	6.00
10-32	21	M8 x 1.25	6.80
12-24	17	M9 x 1.25	7.80
12-28	15	M10 x 1.5	8.50
1/4-20	7	M11 x 1.5	9.50

American Standard Thread		ISO Metric Thread
Thread Size	Tap Drill Size (in.)*	Thread Size	Tap Drill Size(mm)*
1/4-28	3	M12 x 1.75	10.20
5/16-18	F	M14 x 2	12.00
5/16-24	I	M16 x 2	14.00
3/8-16	5/16	M18 x 2.5	15.50
3/8-24	Q	M20 x 2.5	17.50
7/16-14	U	M22 x 2.5	19.50
7/16-20	W	M24 x 3	21.00
1/2-13	27/64	M27 x 3	24.00
1/2-20	29/64	M30 x 3.5	26.50
9/16-12	31/64	M33 x 3.5	29.50

American Standard Thread		ISO Metric Thread
Thread Size	Tap Drill Size (in.)*	Thread Size	Tap Drill Size(mm)*
9/16-18	33/64	M36 x 4	32.00
5/8-11	17/32	M39 x 4	35.00
5/8-18	37/64	M42 x 4.5	37.50
3/4-10	21/32	M45 x 4.5	40.50
3/4-16	11/16	M48 x 5	43.00
7/8-9	49/64	M52 x 5	47.00
7/8-14	13/16	M56 x 5.5	50.50
1"-8	7/8	M60 x 5.5	54.50
1"-14	15/18	M64 x 6	58.00
		M68 x 6	62.00