Extra Long Metric Allen Key Hexagon Hex Ball End Wrench Hand Tools 1.5mm - 10mm

The ball end (on the long arm) allows you to engage a fastener at an angle of up to approximately 25° off-axis — useful when a straight approach is obstructed. The standard hex end (on the short arm) provides a full flat-face contact for maximum torque when tightening or breaking loose a fastener. Use the ball end to start or run down a screw quickly, then switch to the short arm for final torque.

For ISO metric socket-head cap screws (DIN 912), the hex key size matches the socket width across flats: M4 screws use a 3 mm hex key, M5 screws use a 4 mm hex key, and M6 screws use a 5 mm hex key. If you are unsure, check the fastener's datasheet or measure the socket opening with a caliper before ordering.

The black oxide finish provides limited corrosion resistance and is best suited for dry indoor use. For occasional outdoor or damp-environment use, wipe the tools dry after use and apply a light coat of machine oil. For prolonged exposure to moisture or chemicals, consider stainless steel or chrome-vanadium alternatives.

The ball end is designed for access and speed, not maximum torque. At high angles, the contact area between the ball tip and the fastener socket is reduced, which can round out the socket if excessive force is applied. For final tightening to specification, always use the standard hex short arm at 0° (straight engagement).

The Flat Head 5 mm variant features a flat-tipped long arm rather than a ball end, providing full hex contact at 0° engagement in the 5 mm size. This is useful when you need the extended reach of the long arm but require the full torque capacity of a standard hex tip — for example, when tightening a 5 mm socket screw in a deep recess that is still accessible straight-on.

If you need a single size for a specific repair, a 1 or 2 PCS pack is the most economical choice. For workshop stocking or if you frequently lose or misplace small hex keys, the 5, 10, or 15 PCS packs offer a lower per-unit cost. Larger packs are also practical for small businesses or repair shops that service multiple units of the same equipment.

These are metric-sized hex keys and are not interchangeable with SAE/Imperial sizes. For example, a 3 mm key is close to but not the same as 1/8 in (3.175 mm). Using a metric key on an Imperial fastener (or vice versa) risks rounding the socket. If your fasteners are Imperial, please contact us to confirm compatibility before ordering.