ISO 13778:2017 specifies requirements of single-head engineer's wrenches with nominal width across flats from 3,2 to 120.

It specifies the maximum outside dimensions of heads and gives the test torque values. The "lower torque application" designation is in accordance with the smaller head dimensions.

NOTE The wrenches covered by this document are the ones identified in ISO 1703:2005 under reference Nos. 1 1 01 01 0 and 1 1 01 01 1.