Allen Hex Key Long Arm Metric 0.7mm-17mm Hexagonal Wrench Keys Screwdriver 911-L

Match the key size to the across-flats (A/F) dimension of the hex socket in your screw head — not the screw's thread diameter. For example, an M4 socket head cap screw (ISO 4762) typically uses a 3 mm hex key, while an M6 uses a 5 mm key. If you are unsure, use a set of gauge pins or try the next size down first to avoid rounding the socket.

The long arm gives you two advantages: reach and torque. The extended arm can access screws recessed deep inside housings, frames, or counterbores where a short key cannot fit. When used as the driving arm, it also multiplies your hand force, allowing you to apply more torque with less effort — useful for fasteners that have been installed with thread-locking compound or that have corroded slightly.

The nickel-plated finish provides a meaningful improvement in corrosion resistance compared to bare carbon steel, making these keys suitable for general workshop use, occasional outdoor tasks, and environments with moderate humidity. For prolonged exposure to salt spray, standing water, or highly corrosive chemicals, wipe the keys dry after use and apply a light coat of machine oil to maintain the finish.

Yes. Any metric fastener with a hex socket — including socket head cap screws (ISO 4762 / DIN 912), button head screws (ISO 7380), countersunk socket screws (ISO 10642), and set screws / grub screws (ISO 4026–4029) — uses the same hex key size. Select the key that matches the across-flats dimension of the socket, and it will work across all of these fastener types.

If you already have most sizes and only need to replace one or two, individual keys in packs of 1, 2, 5, or 10 are the most cost-effective option. If you are equipping a new toolbox, a service kit, or a workshop station from scratch, the M0.7–M10 set covers the full range of common metric hex sizes in a single purchase and eliminates the need to source each size separately. The set is also a practical choice for technicians who work across multiple machine types with varying fastener sizes.

These are standard L-shaped hex keys and are designed for direct hand use. They are not compatible with T-handle holders or socket drive adapters without a dedicated hex key bit or holder accessory. For applications requiring a T-handle or ratchet drive, look for hex key bits (also called Allen bits) in the corresponding metric sizes instead.

The 5-piece and 10-piece packs offer the lowest per-unit cost and are well suited for stocking a workshop tool crib, equipping multiple service stations, or resale. The 10-piece pack is particularly efficient for high-turnover sizes such as 3 mm, 4 mm, 5 mm, and 6 mm, which are consumed most frequently in general assembly and maintenance work.