Decimal Equivalents, Standard and NPT Drill Sizes, and Sheet Metal Thickness

Fraction (Clearance Hole Size or Thickness)	Decimal (Clearance Hole Size or Thickness)	Bolt, Screw, or NPT Fitting Size	Tap Drill Dia. (Fraction)	Tap Drill Dia. (Decimal)	Number Drill	Letter Drill	Drill Size Alum /  Steel	Sheet Metal Gauge (Steel)
	.0135				80
	.0145				79
	.0149							28
	.0179							26
1/64	.015625
	.0239							24
	.0299							22
1/32	.03125
	.0359							20
3/64	.0469
	.0478							18
	.0520				55
	.0595				53
	.0598							16
	.0600	0-80	3/64				3/64 / 55
1/16	.0625	1/16-60	3/64	.0469
	.0700				50
	.730				49
	.0730		1-64	.0595			53 / 1/16
	.0730		1-72	.0595			53 / 52
	.0747							14
	.0760				48
1/16-27 NPT		1/16-27 NPT		.242		C
5/64	.078125
	.0785				47
	.0810				46
	.0820				45
	.0860				44
	,0860	2-56		.0700			50 / 49
	,0860	2-64		.0700			50 / 48
3/32	.09375	3/32-48		.0760			48
	.0990	3-48		.0785			47 / 44
	.0990	3-56		.0785			45 / 43
	.0980				40
	.0995				39
	.1015				38
	.1040				37
	.1046							12
	.1065				36
7/64	.109375
	.1100				35
	.1110				34
	.1120	4-40		.0890			43 / 41
	.1120	4-48		.0890			42 / 40
	.1130				33
	.1160				32
	.1196							11
	.1200				31
1/8	.125	1/8-40		.1015			38 / 7/64
1/8	.125	5-40		.1015			38 / 7/64
1/8	.125	5-44		.1040			37 /35
1/8-27 NPT		1/8-27 NPT		.332		Q
	.1285				30
	.1345							10
	.1360				29
	.1380	6-32		.1065			36 / 32
	.1380	6-40		.1130			36 / 31
	.1640	8-32		.1360			29 / 27
	.1640	8-36		.1360			29 / 26
	.1405				28
9/64	.140625
	.1440				27
	.1470				26
	.1495				25
	.1520				24
	.1540				23
5/32	.15625
	.1570				22
	.1590				21
	.1610				20
	.1660				19
	.1695				18
11/64	.171875
	.1730				17
	.1770				16
	.1800				15
	.1820				14
	.1850				13
3/16	.1875	3/16-24		.1440			27
3/16	.1875	3/16-32		.1540			23
	.1890				12
	.1900	10-24		.1495			25 / 20
	.1900	10-32		.1590			21 / 18
	.1910				11
	.1935				10
	.1960				9
	.1990				8
	.2010				7
13/64	.203125
	.2040				6
	.2055				5
	.2090				4
	.2130				3
	.2160	12-24		.1770			16 / 12
	.2160	12-28		.1800			14 / 10
7/32	.21875	7/32-24		.1770			16
7/32	.21875	7/32-26		.1800			15
7/32	.21875	7/32-28		.1820			14
	.2210				2
	.2280				1
	.234					A
15/64	.234375
	.238					B
	.242					C
	.246					D
1/4	.250					E
1/4	.250	1/4-20		.2010			7 / 7/32
1/4	.250	1/4-28		.2030		I	3 / 1
1/4-18 NPT		1/4-18 NPT	7/16	.438
	.257					F
	.261					G
17/64	.265625
	.266					H
	.272					I
	.277					J
	.281					K
9/32	.28125
	.290					L
	.295					M
19/64	.296875
	.302					N
5/16	.3125	5/16-18		.2570		F	F / J
5/16	.3125	5/16-24		.2720		I	I / 9/32
	.316					O
	.323					P
21/64	.328125
	.331					Q
	.339					R
11/32	.34375
	.348					S
	.358					T
23/64	.359375
	.368					U
3/8	.375	3/8-16	5/16	.3125			5/16 / Q
3/8	.375	3/8-24		.3320		Q	Q / S
3/8-18 NPT		3/8-18 NPT	9/16	.562
	.377					V
	.386					W
25/64	.390625
	.397					X
	.404					Y
13/32	.40625
	.413					Z
27/64	.421875
7/16	.4375	7/16-14		.3680		U	U / 25/64
7/16	.4375	7/16-20	25/64	.3906			25/64 / 13/32
29/64	.453125
15/32	.46875
31/64	.484375
1/2	.500	1/2-13	27/64	.4219			27/64 / 29/64
1/2	.500	1/2-20	29/64	.4531			29/64 / 15/32
1/2-14 NPT		1/2-14 NPT	45/64	.703
33/64	.515625
17/32	.5315
35/64	.546875
9/16	.5625	9/16-12	31/64	.4844			31/64 / 33/64
9/16	.5625	9/16-18	33/64	.5156			33/64 / 17/32
37/64	.578125
19/32	.59375
39/64	.609375
5/8	.625	5/8-11	17/32	.5312			17/32 / 9/16
5/8	.625	5/8-18	37/64	.5781			37/64 / 19/32
41/64	.640625
21/32	.65625
43/64	.671875
11/16	.6875
45/64	.703125
23/32	.71875
47/64	.734375
3/4	.750	3/4-10	21/32	.6562			21/32 / 11/16
3/4	.750	3/4-16	11/16	.6875			11/16 / 45/64
3/4-14 NPT		3/4-14 NPT	29/32	.906
49/64	.765625
25/32	.78125
51/64	.4796875
13/16	.8125	13/16-20	49/64	.7656			49/64 / 25/32
53/64	.828125
27/32	.84375
55/64	.859375
7/8	.875	7/8-9	49/64	.7656			49/64 / 51/64
7/8	.875	7/8-14	13/16	.8125			13/16 / 53/64
57/64	.890625
29/32	.90625
59/64	.921875
15/16	.9375	15/16-20	57/64	.8906
61/64	.953125
31/32	.96875
63/64	.984375
1	1.00	1-8	7/8	.875			7/8 / 59/64
1	1.00	1-12	15/16	.9375			15/16 / 61/64
1 NPT		1 NPT	1 9/64	1.141