Screwdriver Bit Wera 840/4 Z SB

The Wera 840/4 Z SB screwdriver bit is a precision hex bit engineered for reliable fastening in professional and DIY applications. It has a 6 mm hex tip and an overall length of 152 mm, providing extended reach where standard bits are too short. The bit’s 1/4" hexagonal shank ensures a secure connection with commonly used bit holders, ratchets and screwdriver handles. Supplied in a blister pack, this Wera bit is intended for tasks requiring accurate torque transfer and a stable fit.

Advantages

This screwdriver bit combines a robust hardened tip with precise geometry to reduce cam-out and wear during repeated use. The 152 mm length improves accessibility in recessed or hard-to-reach fasteners while the 6 mm hex profile delivers positive engagement for hex-headed screws and bolts. The standardized 1/4" hex shank fits a wide range of bit holders and hand tools, enabling quick changes and consistent performance.

Suitable for

• Accessing recessed hex screws in machinery and equipment
• Assembly and disassembly of furniture and fixtures with 6 mm hex fasteners
• Use with bit holders, ratchet screwdrivers and cordless drivers that accept 1/4" bits
• Maintenance tasks where extended reach and precise fit are required

Key specifications

• Tip type: 6 mm hexagon
• Overall length: 152 mm
• Shank profile: 1/4" (hexagonal)
• Packaging: blister
• Material and heat treatment: hardened tip for improved wear resistance

How to use

Insert the 1/4" hex shank into a compatible bit holder, ratchet or driver until it seats firmly. Position the 6 mm hex tip into the fastener head, ensuring full engagement before applying torque. Apply steady, controlled force to avoid stripping the fastener; for power tools, use appropriate torque settings to match the fastener and application. After use, store the bit in its blister or a dedicated bit holder to protect the tip and maintain geometry.

Usage recommendations

For optimal longevity, avoid using the bit on damaged or rounded fasteners. When working with power tools, select torque and speed settings that suit the fastener size and material. Inspect the tip regularly for wear and replace if deformation or excessive rounding is observed.