Hex Socket Bit 4 mm, 3/8" Drive, 50 mm Length — Proxxon

Proxxon 4 mm hex socket bit with a 3/8" drive and 50 mm length is a medium-length tool insert designed to engage 4 mm hex (Allen) fasteners. Intended for use with 3/8" drive ratchets, torque wrenches and extension bars, this bit provides a precise fit for assembly, maintenance and repair work in mechanical, automotive and equipment servicing applications.

Advantages

The bit is manufactured to provide accurate hex engagement, reducing the risk of rounding or slipping on fasteners. Its 50 mm overall length offers improved access to recessed or partially obstructed fasteners while maintaining sufficient stiffness for controlled torque application. Compatibility with common 3/8" drive handles and extensions enables flexible use across workshop sockets and hand tools. The standardized 4 mm hex profile ensures interchangeability with other 4 mm fastener-driven operations.

Suitable for

• Assembly and disassembly of mechanical components with 4 mm hex fasteners
• Automotive maintenance tasks requiring medium-reach hex access
• Equipment servicing where 3/8" drive tools are used
• Workshop and professional repair environments needing precise hex engagement

Key specifications

• Hex size: 4 mm
• Drive type: 3/8" drive compatibility
• Overall length: 50 mm
• Tool type: hex (Allen) socket bit

How to use

Insert the hex socket bit into a compatible 3/8" drive ratchet, torque wrench or extension bar until it seats securely. Align the 4 mm hex tip with the fastener and apply steady torque, ensuring the bit remains fully engaged to minimize cam-out. For tightened or seized fasteners, use a torque-rated handle or breaker bar as appropriate and avoid excessive force that could damage the fastener head or bit. After use, store the bit in a suitable holder to prevent corrosion and maintain tip geometry.

Usage recommendations

Use this 4 mm hex socket bit with properly rated 3/8" drive tools and select torque settings appropriate for the fastener material. Regularly inspect the bit tip for wear and replace when rounding or deformation is visible to maintain secure engagement and safe operation.