This standard deals with double head open ended engineers wrenches with unequal jaw widths; it includes the dimensions and the designation of these wrenches. The double head open ended engineers wrenches have to couply with the test torques series C according to DIN 899.
DIN 3110:1987 history
2007DIN 3110:2007-09 Engineers wrenches, double head - Test torques series C
2007DIN 3110:2007 Engineers wrenches, double head - Test torques series C
1987DIN 3110:1987 Engineers wrenches, double head, open end, with unequal jaw widths; test torques series C