Wera 840/1 ZBO Hex Pinned Security Bit Extra Tough 4mm 25mm Pack of 1

The Wera 840/1 ZBO 4mm Hex Pinned Security Bit is engineered for heavier-duty applications where larger tamper-proof fasteners are required. This 4mm size is commonly specified in machinery assembly, automotive applications, and industrial equipment where both substantial torque transmission and security against unauthorised access are essential. The tough viscous construction provides the durability needed for professional tradespeople working daily with hard materials and demanding fastening applications. Featuring Wera's advanced Hex-Plus technology, this bit delivers superior performance by offering a significantly greater contact surface within the screw head. This innovation reduces the notching effect to a minimum and virtually eliminates screw head damage, ensuring your fasteners remain serviceable throughout their lifetime. The hexagon socket BO screw design, with its characteristic protruding pin in the drive profile, prevents any unauthorised loosening since normal hex tools