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Wrench size
From Wikipedia, the free encyclopedia
Width across flats is the distance between two parallel surfaces on the head of a screw or bolt, or a nut, mostly for torque transmission by positive locking.
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The term width across flats (AF) is used for the following forms:
- 2-socket = round material with two surfaces
- 4-socket = profile square section
- 6-socket, 8-square = regular polygons