PROTO, Industrial Tools

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Conversion Charts


STANDARD WRENCH SIZING CHART
Nominal Opening of Proto Wrenches or Sockets in Inches to Fit Standard Bolt Heads and Screw Heads

WRENCH OR
SOCKET SIZE
SQUARE AND HEX BOLTS, CAP SCREWS & SQUARE & HEX LAG SCREWS
HEAVY HEX BOLTS & SCREWS
HEX FLANGE SCREWS
TAPPING SCREWS
HEX WASHER HEAD TAPPING SCREWS
HEX HEAD MACHINE SCREWS
HEX WASHER HEAD MACHINE SCREWS
SQUARE HEAD SET SCREWS
ACROSS FLATS
DECIMAL EQUIV.
1/8
0.1250
#1&2
#2&3
#1&2
#2&3
5/32
0.1562
3/16
0.1875
#3,4,5
#4&5
#3,4,5
#4&5
#10
1/4
0.2500
#6,7,8
#6,7,8
#6&8
#6&8
1/4
9/32
0.2812
#10
5/16
0.3125
#10&12
#10&12
#10&12
#10&12
5/16
11/32
0.3438
3/8
0.3750
1/4
1/4
1/4
1/4
1/4
1/4
3/8
7/16
0.4375
1/4
7/16
1/2
0.5000
5/16
5/16
5/16
5/16
5/16
5/16
1/2
9/16
0.5625
3/8
3/8
3/8
3/8
3/8
3/8
9/16
5/8
0.6250
7/16
7/16
5/8
11/16
0.6875
3/4
0.7500
1/2
1/2
3/4
13/16
0.8125
9/16
9/16
7/8
0.8750
1/2
7/8
15/16
0.9375
5/8
5/8
1
1.0000
1
1 1/16
1.0625
5/8
1 1/8
1.1250
3/4
3/4
1 1/8
1 1/4
1.2500
3/4
1 1/4
1 5/16
1.3125
7/8
1 3/8
1.3750
1 3/8
1 7/16
1.4375
7/8
1 1/2
1.5000
1
1 1/2
1 5/8
1.6250
1
1 11/16
1.6875
1 1/8
1 13/16
1.8125
1 1/8
1 7/8
1.8750
1 1/4
2
2.0000
1 1/4
2 1/16
2.0625
1 3/8
2 3/16
2.1875
1 3/8
2 1/4
2.2500
1 1/2
2 3/8
2.3750
1 1/2
2 7/16
2.4375
1 5/8
2 9/16
2.5625
1 5/8
2 5/8
2.6250
1 3/4
2 3/4
2.7500
1 3/4
2 13/16
2.8125
1 7/8
2 15/16
2.9375
1 7/8
3
3.0000
2
3 1/8
3.1250
2
3 3/8
3.3750
2 1/4
3 1/2
3.5000
2 1/4
3 3/4
3.7500
2 1/2
3 7/8
3.8750
2 1/2
4 1/8
4.1250
2 3/4
4 1/4
4.2500
2 3/4
4 1/2
4.5000
3
4 5/8
4.6250
3
4 7/8
4.8750
3 1/4
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
4 1/4
6 7/8
6.8750
4 1/2
7 1/4
7.2500
4 3/4
7 5/8
7.6250
5
8
8.0000
5 1/4
8 3/8
8.3750
5 1/2
8 3/4
8.7500
5 3/4
9 1/8
9.1250
6