Hex Key Proline 3 mm | Proline Tools 48443, single-piece Allen key

Proline 3 mm hex key (single-piece Allen key) is a compact hand tool designed for tightening and loosening metric hex-head fasteners with a 3 mm drive. Manufactured from quenched and tempered steel with a polished chromium finish, this single-piece hex key offers a simple, durable solution for light to medium workshop, repair and assembly tasks that require precise control in confined spaces.

Advantages

The solid one-piece construction provides consistent torque transfer and resists twisting under normal use. Heat treatment (quenching and tempering) increases strength and wear resistance while the polished chromium finish improves corrosion protection and allows smooth insertion into fasteners. Its compact size makes it easy to carry in a tool roll, pocket or small toolkit and provides good access in tight or recessed hex sockets.

Suitable for

• Furniture assembly and adjustment
• Bicycle maintenance and component adjustment
• Electronics and precision mechanical repairs
• General workshop and hobby tasks requiring a 3 mm hex drive

Key specifications

• Tool type: single-piece hex (Allen) key
• Drive size: 3 mm
• Material: quenched and tempered steel
• Surface finish: polished chromium
• Format: L-shaped single key for manual use

How to use

Select the 3 mm hex key and align the short or long arm with the hex socket of the fastener depending on access and leverage needs. Insert the key fully into the fastener socket to avoid rounding the edges, then apply steady torque to tighten or loosen. Use the long arm for increased leverage when more force is required and the short arm for better access in confined spaces. Inspect the tool and fastener before use to ensure correct fit and to avoid damage.

Usage recommendations

For best results, keep the hex key clean and dry and store it in a protective pouch or toolbox to preserve the polished chromium finish. Avoid using excessive force beyond hand torque or using the key as a pry bar. If a fastener is corroded or extremely tight, consider applying penetrating lubricant and use appropriate safety measures to prevent slippage or injury.