Standard/Metric Wrench Chart

If your tool box is like mine, you have an assortment of wrenches, but invariably need a second one for the same bolt and don't have the extra standard or metric one of the same size. Post this chart on your shop wall or tool box inner lid to help find a close wrench fit. (Printer-friendly PDF)

STANDARD / METRIC
WRENCH CONVERSION CHART

Bolt Diameter

Standard

Metric

1/8"

5/16"

8 mm

3/16"

3/8"

10 mm

1/4"

7/16"

11 mm

5/16"

1/2"

13 mm

3/8"

9/16"

14 mm

7/16"

5/8"

16 mm

1/2"

3/4"

19 mm

9/16"

13/16"

21 mm

  7/8" 22 mm

5/8"

15/16"

24 mm

  1" 25 mm

3/4"

1-1/8"

29 mm

  1-1/4" 32 mm

7/8"

1-5/16"

34 mm

  1-3/8" 35 mm

1"

1-1/2"

38 mm

  1-5/8" 41 mm
1-1/8" 1-11/16" 43 mm
  1-3/4" 45 mm
1-1/4" 1-7/8" 48 mm
1-3/8" 2" 51 mm
1-1/2" 2-1/4" 57 mm
1-5/8" 2-1/2" 64 mm
1-3/4" 2-5/8" 67 mm
  2-3/4" 70 mm
1-7/8" 2-15/16" 75 mm
  3" 76 mm
2" 3-1/8" 80 mm
  3-1/4" 83 mm
2-1/4" 3-1/2" 89 mm
  3-3/4" 95 mm
2-1/2" 3-7/8" 99 mm
  4" 102 mm
2-3/4" 4-1/4" 108 mm
  4-1/2" 114 mm
3" 4-5/8" 118 mm
3-1/4" 5" 127 mm
3-1/2" 5-3/8" 137 mm
  5-1/2" 140 mm
3-3/4" 5-3/4" 146 mm
  6" 152 mm
  6-1/2" 165 mm
  7" 178 mm

Webpage maintained by:
Bob Schultheis
Natural Resource Engineering Specialist
Email comments to: schultheisr@missouri.edu
Last revised: 01/14/2013

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