This is a metric long arm Torx (TX) star and hex (Allen) key set designed for access to recessed or hard-to-reach socket fasteners, providing greater reach and increased leverage compared with short-leg keys. The 18-piece set combines the common metric hex sizes used on machine screws and bolts with Torx sizes that are widely specified on vehicle and equipment assemblies, making it a versatile workshop and service tool.

Each key is manufactured from chrome vanadium (Cr-V) steel that has been heat treated and tempered to resist torsional failure under load. The keys have a protective black oxide finish to reduce corrosion and minimise light surface wear; tips are chamfered to ease initial engagement. Drive types included are internal hex (Allen) and Torx star (TX), supplied as long-arm L-keys to give leverage on tight fastenings and reach into deep sockets. The metric sizing conforms to common DIN/ISO dimensional conventions for internal hex and Torx drivers and is compatible with the corresponding BS and ISO fastener specifications typically used in industry.

Typical applications include plant and machinery maintenance, automotive and motorcycle repair, bicycle servicing, assembly and maintenance of HVAC units, and general engineering where recessed hex or Torx fasteners are fitted. The Torx keys are especially useful where manufacturers specify star fittings for tamper resistance and improved torque transfer; the hex keys cover everyday machine screw and furniture fittings. The long arm format is useful for applying higher torque with the short end in the socket or for reaching into assemblies where the head of the fastener sits below surrounding components.

Key benefits are corrosion resistance from the black oxide finish, improved strength and torsional resistance from the Cr-V heat treatment, and broad compatibility with standard metric hex and Torx fasteners. The chamfered tips reduce wear on fastener sockets and aid faster engagement, while the long arm geometry gives mechanical advantage without needing additional tools.

Duchy Fasteners stocks this 18-piece long arm TX star & hex set in a compact fold-out holder, typically covering hex sizes 1.5–10 mm and Torx sizes T10–T50; we also supply individual lengths and alternative pack sizes across our hand tool range.