Long Hex Key Wrench (5x10pcs)

Five millimetres turns M6 socket head cap screws, and M6 is the size a designer reaches for when a fixing has to be genuinely secure without being heavy. It holds machine covers and guards, pump and motor mountings, brackets and frames, bicycle components almost throughout, furniture and fitted joinery, hydraulic and pneumatic fittings, and a great deal of the imported machinery in Sri Lankan workshops.

Because it is used constantly, it also wears. And a worn hex key is a genuinely dangerous thing to have in a drawer, because it does not look worn. The corners round off at the very tip first, where all the work happens, and the key still slides into a recess and still turns most screws. What it will not do is turn a tight one without chewing the socket, and by the time you notice, the fastener is damaged rather than the key.

There is a repair for this and it is worth knowing. Square the worn end off on a bench grinder, taking a little at a time and dipping the key in water constantly so the steel never changes colour. Colour means the temper has been drawn and the key will be soft where it matters. Done properly you expose fresh full size hexagon behind the wear and the key is as good as it was. Done in one continuous pass on a hot wheel you have made a key that twists.

That single trick is the reason a hex key is a repairable tool, and it is worth trying before you buy. When it is past squaring, this is the size to keep a spare of.

The long pattern suits M6 work because covers, guards and frames put screws down between components where reach decides whether you need to strip anything else off first.

It is forged chrome vanadium, then hardened and tempered, which is the combination that lets the corners stay sharp through exactly the sort of daily use that wore out the last one.

Buyers are general and machinery workshops, motorcycle and cycle trades, pump and generator servicing, joiners and shopfitters, maintenance technicians, and hardware dealers who sell more 5mm keys than any other single size.

The figure in brackets in the catalogue name is Harden's carton quantity. What we sell is one 5mm key. Message 94 77 111 8880 for price and delivery anywhere in the island.