Metric Allen Key Set Hexagon Hex Ball End Wrench 9 Piece Hand Tools 1.5mm - 10mm

Medium Length keys are suited for most standard applications where space is not a limiting factor. Extra Length keys have a longer arm, which provides more leverage when driving fasteners and allows access to deeply recessed sockets that a medium-length key cannot reach.

The ball end is designed for off-angle access and driving at angles up to approximately 30°. For final tightening to full torque, use the straight short arm of the key, which provides maximum contact with the fastener socket and reduces the risk of rounding.

Chrome Vanadium (CR-V) is a widely used tool steel that offers a good balance of toughness, hardness, and corrosion resistance — suitable for everyday DIY and mechanical work. S2 Alloy Steel is harder and more impact-resistant, making it better suited for high-torque applications and professional use where fasteners may be tighter or more stubborn.

No. This set is metric only, covering sizes 1.5 mm through 10 mm. Metric hex keys are not interchangeable with SAE/imperial hex fasteners. If you need imperial sizes, please check our separate SAE Allen key listings.

These keys are designed for hex socket (Allen) fasteners — including socket head cap screws, set screws (grub screws), button head bolts, and flat head socket screws — in metric sizes M1.5 through M10. They are commonly used in furniture assembly, bicycles, motorcycles, machinery, and electronics enclosures.

The hex key size must match the across-flats measurement of the socket in your fastener head. If you are unsure, start with a key that fits snugly without play — a loose fit will round the socket. Common sizes for furniture are 4 mm and 5 mm; bicycle components frequently use 2.5 mm, 4 mm, and 5 mm; machinery set screws often require 3 mm, 4 mm, or 6 mm.