PROTO, Industrial Tools

Phone: 800-800-TOOL

Conversion Charts


STANDARD WRENCH SIZING CHART
Nominal Opening of Proto Wrenches or Sockets in Millimeters to Fit Standard Nuts

WRENCH OR
SOCKET SIZE
SQUARE NUTS & HEAVY SQUARE NUTS
TRACK, HEAVY HEX & SQUARE, FLAT AND JAM NUTS
SQUARE MACHINE SCREW NUT
HEX NUTS & FLAT CASTLE, SLOTTED AND HAM HEX NUTS
HEX FLANGE NUTS
TRACK BOLT NUTS
HEX LOCK NUTS
ACROSS FLATS
DECIMAL EQUIV.
1/8
0.1250
5/32
0.1562
#0&1
3/16
0.1875
#2&3
1/4
0.2500
#4
#4
9/32
0.2812
5/16
0.3125
#5&6
#6
#6
11/32
0.3438
#8
#8
#8
3/8
0.3750
#10
#10
#10
7/16
0.4375
1/4
#12&14
1/4
#12&14
#12&14
1/2
0.5000
1/4
1/4
5/16
5/16
5/16
9/16
0.5625
5/16
5/16
5/16
3/8
3/8
3/8
5/8
0.6250
3/8
3/8
11/16
0.6875
3/8
3/8
7/16
7/16
7/16
3/4
0.7500
7/16
7/16
1/2
1/2
1/2
13/16
0.8125
1/2
7/8
0.8750
1/2
1/2
9/16
9/16
9/16
15/16
0.9375
9/16
5/8
5/8
5/8
1
1.0000
5/8
1 1/16
1.0625
5/8
5/8
1 1/8
1.1250
3/4
3/4
3/4
3/4
1 1/4
1.2500
3/4
3/4
3/4 & 13/16
1 5/16
1.3125
7/8
7/8
7/8
1 3/8
1.3750
1 7/16
1.4375
7/8
7/8
7/8
1 1/2
1.5000
1
1
15/16 & 1
1
1 5/8
1.6250
1
1
1 & 11/16
1 11/16
1.6875
1 1/8
1 1/8
1 1/8
1 1/8
1 13/16
1.8125
1 1/8
1 1/8
1 1/8
1 7/8
1.8750
1 1/4
1 1/4
1 1/4
2
2.0000
1 1/4
1 1/4
2 1/16
2.0625
1 3/8
1 3/8
1 3/8
2 3/16
2.1875
1 3/8
1 3/8
2 1/4
2.2500
1 1/2
1 1/2
1 1/2
2 3/8
2.3750
1 1/2
1 1/2
2 7/16
2.4375
2 9/16
2.5625
1 5/8
2 5/8
2.6250
2 3/4
2.7500
1 3/4
2 13/16
2.8125
2 15/16
2.9375
1 7/8
3
3.0000
3 1/8
3.1250
2
3 3/8
3.3750
3 1/2
3.5000
2 1/4
3 3/4
3.7500
3 7/8
3.8750
2 1/2
4 1/8
4.1250
4 1/4
4.2500
2 3/4
4 1/2
4.5000
4 5/8
4.6250
3
4 7/8
4.8750
5
5.0000
3 1/4
5 1/4
5.2500
3 1/2
5 3/8
5.3750
3 1/2
5 5/8
5.6250
3 3/4
5 3/4
5.7500
3 3/4
6
6.0000
4
6 1/8
6.1250
4
6 1/2
6.5000
6 7/8
6.8750
7 1/4
7.2500
7 5/8
7.6250
8
8.0000
8 3/8
8.3750
8 3/4
8.7500
9 1/8
9.1250