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