PROTO, Industrial Tools

Phone: 800-800-TOOL

Conversion Charts


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

Locate thread diameter of nut in left column. Then move across to box which has proper identification of nut at top of vertical column. The size in this particular box is the nominal opening size in inches of the PROTO wrench and sockets that will fit.

WRENCH OR SOCKET SIZE ACROSS FLATS
HEX NUTS
STYLE 1
HEX NUTS
STYLE 1
SLOTTED AND
HAM HEX NUTS
HEAVY HEX NUTS
 
Use wrench or socket size shown below
3.20
M1.6 x 0.35
4.00
M2 x 0.4
5.00
M2.5 x 0.45
5.50
M3 x 0.5
M3 x 0.5
6.00
M3.5 x 0.6
M3.5 x 0.6
7.00
M4 x 0.7
M4 x 0.7
8.00
M5 x 0.8
M5 x 0.8
M5 x 0.8
10.00
M6 x 1
M6 x 1
M6 x 1
13.00
M8 x 1.25
M8 x 1.25
M8 x 1.25
15.00
M10 x 1.5
M10 x 1.5
M10 x 1.5
16.00
M10 x 1.5
M10 x 1.5
M10 x 1.5
18.00
M12 x 1.75
M12 x 1.75
M12 x 1.75
21.00
M14 x 2
M14 x 2
M14 x 2
M12 x 1.75
24.00
M16 x 2
M16 x 2
M16 x 2
M14 x 2
27.00
M16 x 2
30.00
M20 x 2.5
M20 x 2.5
M20 x 2.5
34.00
M20 x 2.5
36.00
M24 x 3
M24 x 3
M24 x 3
M22 x 2.5
41.00
M24 x 3
46.00
M30 x 3.5
M30 x 3.5
M30 x 3.5
M27 x 3
50.00
M30 x 3.5
55.00
M36 x 4
M36 x 4
M36 x 4
60.00
M36 x 4
65.00
70.00
M42 x 4.5
75.00
80.00
M48 x 5
85.00
90.00
M56 x 5.5
95.00
100.00
M64 x 6
105.00
110.00
M72 x 6
115.00
120.00
M80 x 6
130.00
135.00
M90 x 6
145.00
150.00
M100 x 6