Square bit set Bosch Vierkant-Bit 3 extra hard C 6.3, 3 pieces

Bosch Vierkant-Bit 3 extra hard C 6.3, 3 pieces is a compact set of square-drive bits engineered for driving square-head fasteners. The three-piece assortment is made from a hardened steel grade to provide increased wear resistance and maintain bit geometry under repeated torque. Each bit is designed to fit a standard 6.3 mm (1/4") bit holder, making the set compatible with common manual drivers and powered screwdrivers or impact drivers used in assembly, maintenance and repair work.

Advantages

The extra-hard material construction improves lifespan in high-torque and frequent-use scenarios while reducing deformation at the contact points. Uniform 6.3 mm (1/4") shanks ensure compatibility with common bit holders and adapters. The small, three-piece format simplifies storage and selection for specific fastener sizes and keeps replacement bits readily available on the job.

Suitable for

• Driving square-head screws in furniture assembly and joinery
• Maintenance and repair tasks on equipment using square-drive fasteners
• General workshop and on-site fastening where compact bit sets are preferred

Key specifications

• Bit type: square (Robertson) drive
• Material hardness: extra hard/hardened steel
• Shank diameter: 6.3 mm (1/4") standard
• Pieces in set: 3
• Intended use: manual drivers and compatible power tools

How to use

Select the appropriate square bit size for the fastener and insert the 6.3 mm (1/4") shank securely into the bit holder of a hand driver or power tool. Apply steady axial pressure to seat the bit in the screw recess, then operate the driver at a controlled speed to avoid cam-out. For power tools, start at low speed to ensure correct engagement, and increase torque gradually as needed. After use, inspect the working tip for wear and replace the bit if the square profile shows rounding or deformation.

Usage recommendations

Use the bits with the correct driver torque setting and avoid excessive side loading. Store the set in a dry place and replace bits that exhibit visible wear to maintain fastening quality and reduce risk of screw damage.