Long Hex Key Wrench (10x8pcs)

Every nine piece hex key set on the market runs out here. So the 10mm is the biggest key in the box, it is the one reached for when a fixing is stubborn, and it is therefore the one that gets bent, twisted or left behind on a job. Above this size there are no sets at all and every key is bought on its own.

It drives M12 socket head cap screws, which hold machine bases and frames, large motor and gearbox mountings, hydraulic components, structural brackets, and heavy vehicle and plant assemblies.

The thing worth talking about at 10mm is what happens when the fastener will not turn, because this is exactly where people improvise. The arm on a long key is a comfortable handful, and when a fixing resists the natural next step is to slip a length of pipe over the arm for more leverage. It is worth being clear about what that does. The key was designed so that a strong person pulling on the bare arm applies roughly the force the fastener can take. Double the arm with a pipe and you have doubled the force at the tip while the recess in the screw head has stayed exactly the same size. Something then gives, and it is usually the corners of the recess, occasionally the key, and once in a while your knuckles against whatever is behind the machine.

If a fixing needs more than the bare key, the honest answer is a different tool rather than a longer arm: a hex bit in a socket, on a proper bar, where the force runs straight down the axis of the screw and you have both hands and a stance behind it.

Two smaller habits pay off here as well. Wear a glove or fold a cloth over the arm, because a thin steel bar under real load concentrates on a very small patch of palm. And keep the key square to the screw, since a key pulled off axis loads the corners rather than the flats.

Forged chrome vanadium, hardened and tempered.

Buyers are machinery and plant fitters, hydraulic engineers, fabricators, heavy vehicle and earthmoving workshops, maintenance teams, and hardware dealers who find the 10mm is the size customers replace most.

The bracket in the catalogue title carries Harden's carton figure, not the quantity sold. This is one 10mm key. Message 94 77 111 8880 and we will send it anywhere in the island.