Screwdriver Bit Wera 840/4 IMP DC Hex-Plus DIY

The Wera 840/4 IMP DC Hex-Plus DIY screwdriver bit is a 4 mm hex tip insert designed for general DIY and light professional tasks. With a length of 50 mm and a 1/4 inch (25.4 mm) hexagonal shank, this bit is made in the Czech Republic and built for precise engagement with hex fasteners. The Hex-Plus geometry reduces contact stress on screw heads, improving torque transfer and helping prevent rounding of fasteners during assembly or disassembly.

Advantages

The Hex-Plus design increases contact area between the bit and the screw, which lowers the likelihood of cam-out and decreases wear on both bit and fastener. The 50 mm working length provides reach into slightly recessed screws while the standardized 1/4 inch hex shank ensures compatibility with common bit holders, quick-change chucks, and impact drivers that accept hex inserts. Manufactured under controlled conditions, the bit offers consistent dimensions and durability for repeated use.

Suitable for

• Home improvement and furniture assembly
• Electronics enclosures and panel fastening
• Light mechanical repairs and maintenance
• Use with manual bit drivers, cordless screwdrivers, and compatible impact drivers

Key specifications

• Tip geometry: Hex-Plus for reduced screw head wear
• Tip size: 4 mm hex
• Overall bit length: 50 mm working length
• Shank type: Hexagonal 1/4 inch (25.4 mm) shank for standard bit holders
• Country of manufacture: Czech Republic

How to use

Insert the 1/4 inch hex shank into a compatible bit holder, quick-change chuck, or impact screwdriver. Place the 4 mm Hex-Plus tip squarely into the matching hex fastener, apply steady axial pressure, and drive or remove the screw at moderate speed. For recessed or hard-to-reach fasteners, use the full 50 mm length to reach the screw head while maintaining alignment to avoid side loading.

Usage recommendations

For best results, use the bit with drivers that hold the shank securely and avoid excessive side load. When working with sensitive or soft screw heads, operate at controlled speeds and torque settings to minimize deformation. Inspect the tip before use and replace the bit if signs of wear or rounding appear to preserve fastener integrity.