US Screw size conversion chart:



Screw Size
Inch Decimal
Nearest Fraction
Metric Equivalent
#0 
.060 in.
1/16" 
1.52 mm
#1
.073 in.  
5/64"
1.85 mm
#2
.086 in.  
3/32"
2.18 mm
#3
.099 in.  
7/64"
2.51 mm
#4
.112 in.  
7/64"
2.84 mm
#5
.125 in.  
1/8"
3.18 mm
#6
.138 in.  
9/64"
3.51 mm
#8
.164 in.  
5/32"
4.17 mm
#10
.190 in.  
3/16"
4.83 mm
#12
.216 in.  
7/32"
5.49 mm
#14
.250 in.  
1/4"
6.35 mm


US Fraction to Metric mm equivalent chart:


US
Metric

Cont. US
Cont. Metric
1/16"
.59 mm

1-3/8"
4.93 mm
1/8"
.18 mm

1-1/2"
8.10 mm
3/16"
.76 mm

1-5/8"
1.28 mm
1/4"
.35 mm

1-3/4"
4.45 mm
5/16"
.94 mm

1-7/8"
7.63 mm
3/8"
.53 mm

2"
0.80 mm
7/16"
1.11 mm

2-1/4"
7.15 mm
1/2"
2.70 mm

2-1/2"
3.50 mm
9/16"
4.29 mm
-3/4"
9.85 mm
5/8"
5.88 mm
3"
6.20 mm
11/16"
7.46 mm
3-1/4"
2.55 mm
3/4"
9.05 mm
3-1/2"
8.90 mm
7/8"
2.23 mm
3-3/4"
5.25 mm
1"
5.40 mm
4"
01.6 mm
1-1/4"
1.75 mm