Sturtevant Richmont 819753 Torque Wrench Head, Interchangeable, Open-End, 60mm, 400 Nm Torque

The Open-End Interchageable Wrench Heads have the U-bottom design. Sturtevant Richmont changed from the V-bottom to the U-bottom to increase durability. From an engineering standpoint, a rounded corner distributes the stress vectors more evenly than designs that have intersecting planes.