Hex key Proline 4 mm – Proline 48568 single hex key (metric)

Proline 48568 single hex key is a metric 4 mm Allen wrench designed for driving hex fasteners in a variety of assembly, maintenance and repair tasks. The tool is made from quenched and tempered steel with a polished chromium finish, offering a compact, single-piece design that is convenient for storage and repetitive use. Its 4 mm tip fits standard metric hex screws commonly found in furniture, bicycles, household appliances and light machinery.

Advantages

The hardened and tempered steel construction increases durability and resistance to bending or rounding under torque. The polished chromium finish provides corrosion resistance and smooth surface quality for easier handling and reduced wear. The single-piece design is compact and lightweight, allowing access to confined spaces and straightforward manual operation with consistent fit on 4 mm hex fasteners.

Suitable for

• Assembling and tightening furniture with 4 mm hex fasteners
• Bicycle maintenance where 4 mm Allen keys are required
• Repairing small machines and household appliances with metric hex screws
• DIY projects and professional maintenance tasks needing a reliable 4 mm hex key

Key specifications

• Tip size: 4 mm (metric)
• Material: quenched and tempered steel
• Finish: polished chromium
• Design: single-piece straight hex key
• Drive type: internal hex (Allen)

How to use

Insert the 4 mm tip into the hex recess of the fastener making sure it seats fully to avoid rounding. Apply steady torque by turning the hex key in the required direction; use controlled force to prevent stripping the screw head. For tight fasteners, position the tool for maximum leverage while ensuring the key remains aligned with the fastener axis. After use, wipe clean and store in a toolbox or holder to protect the polished finish.

Usage recommendations

Use the Proline 4 mm hex key for hand-driven tasks; avoid applying impact or excessive torque beyond the tool’s design limits. Keep the tip clean and free from debris to maintain good engagement with fastener heads. For frequent or high-torque applications, consider using a longer or T-handle hex key to increase leverage while reducing stress on the tool and fastener.