Diameter/Decimal/Metric Chart for Small Diameters

Gauge
or Diameter

Decimal (in)

mm

No. 0000

0.021

.53

No. 000

0.034

.86

No. 00

0.047

1.19

No. 0

0.060

1.524

No. 1

0.073

1.854

No. 2

0.086

2.184

No. 3

0.099

2.515

No. 4

0.112

2.845

No. 5

0.125

3.175

No. 6

0.138

3.505

No. 8

0.164

4.166

No. 10

0.190

4.826

No. 12

0.216

5.484

Fastener Conversion Chart

Inch Equivalent

Metric Size-Pitch
ISO and IFI Rec.

UNC

UNF

1 - 64

1 - 72

M2 x 0.4

3 - 48

3 - 56

M2.5 x 0.45

4 - 40

4 - 48

M3 x .05

6 - 32

6 - 40

M3.5 x .06

8 - 32

8 - 36

M4 x .07

10 - 24

10 - 32

M5 x .08

1/4 - 20

1/4 - 28

M6 x 1

5/16 -18

5/16 - 24

M8 x 1.25

3/8 -16

3/8 - 24

M10 x 1.5

7/16 -14

7/16 - 20

M12 x 1.75

1/2 - 13

1/2 - 20

M14 x 2

5/8 - 11

5/8 - 18

M18 x 2

3/4 - 10

3/4 - 16

M20 x 2.5

1 - 8

1-12

M24 x 3

1-1/4 - 7

1-1/8 - 12

M30 x 3.5

1-1/2 - 6

1-1/4 - 12

M36 x 4