Ratchetable open-ended wrench

The inventions discloses a ratchetable open-ended wrench for turning a workpiece (W) having a drive end with at least one pair of opposed contact edges (WS), comprising: a handle (H) with a first end; a wrench head (100) including a base portion (200); a first jaw (110) extending outwardly from the base portion (200) and including a first driving wall (114) disposed in a first plane; a second jaw (120) extending outwardly from the base portion (200) of the wrench head 100 such that the first and the second jaws define a drive opening configured to receive the drive end of the fastener (W), the second jaw including a rear-end wall (127) disposed in a second plane adjacent the base portion (200); and an auxiliary jaw (140) including a driving surface (143) and being slidably received in the second jaw (120) such that the driving surface (143) of the auxiliary jaw (140) extends outwardly into the drive opening and the rear-end wall (127) is disposed between the auxiliary jaw (140) and the base portion (200), wherein the drive end of the fastener (W) is slidably receivable in the drive opening of the wrench head (100) such that the fastener (W) can be rotated in a first direction by the first driving wall (114) and the rear-end wall (127).