Nut Driver Bit Wera 8790 HMA

The Wera 8790 HMA nut driver bit is designed for driving hexagonal fasteners with precision. With a 1/4" (25.4 / 4 mm) shank and a 23 mm length, this bit provides a compact profile for use in confined spaces while delivering a secure engagement with fastener heads. Manufactured by Wera, the bit is intended for repeated use in workshop and field conditions where consistent fit and durability are required.

Advantages

The bit combines a standardized 1/4" shank for compatibility with common bit holders and quick-change systems and a short overall length that improves access in tight assemblies. Its hex driver geometry reduces cam-out and ensures stable torque transfer. The construction and finish of the bit are chosen to resist wear during normal professional and DIY applications, maintaining a reliable mating with hex fasteners over time.

Suitable for

• Assembly and disassembly of small machinery and appliances
• Electrical and electronics installation work requiring compact bits
• Maintenance tasks in confined spaces such as automotive or HVAC systems
• General DIY projects involving hex-head screws and small bolts

Key specifications

• Shank size: 25.4 / 4 mm (1/4")
• Overall length: 23 mm
• Drive type: hex nut driver geometry
• Compatibility: fits standard 1/4" bit holders and quick-change chucks
• Construction: hardened steel with wear-resistant finish

How to use

Insert the Wera 8790 HMA nut driver bit into a compatible 1/4" bit holder, ratchet, or screwdriver handle. Ensure the bit seats fully in the holder before applying torque. Use steady, controlled force to engage the hex fastener and avoid excessive impact or over-torquing that can damage both fastener and bit. For repeated fastening tasks, verify the bit remains free of debris and that the hex profile is not rounded before continuing work.

Usage recommendations

Store the bit in a dry place and keep it in a dedicated bit organizer to prevent loss and reduce wear. For tasks requiring higher torque or impact drivers, select a bit and holder specifically rated for those applications to avoid premature wear or damage.