Steel: 6140CrV 44-48 HRC Nickel-plating A: 19 mm; B: 21 mm; C1: 8 mm; C2: 9 mm; Length: 150 mm A box-end wrench is necessary for servicing hydraulic and pneumatic systems. It is a hexagonal profile with a slot for fitting the wrench onto a pipeline. The profile of the box-end wrench is more solid and tall compared to the open-end wrench, which increases the contact area and reduces the risk of fastener deformation. The working profile of the box-end wrench is offset by 15º from the longitudinal axis, providing more versatility when working in confined spaces. The wrenches are made of chrome-vanadium steel. Nickel-plating with a protective lacquer layer provides additional corrosion resistance.