Long Hex Key Wrench (14x1pc)

Above 10mm, a large hex socket is very often not a cap screw but a PLUG. Gearbox and differential drain and fill plugs, hydraulic port and reservoir plugs, axle and final drive plugs, compressor and pump drain points and sump plugs on a good deal of imported machinery all use a square shouldered plug with a hexagon socket sunk into it. That is why a workshop with no interest in large cap screws still needs large hex keys: without one, an oil change on the machine simply cannot start.

Plugs behave differently from cap screws and it is worth knowing how. They are usually in cast iron or aluminium housings, they are often the lowest point on the assembly so water and grit collect around them, and they may have been in place since the machine was built. On top of that the socket is frequently filled solid with old oil, sludge and road dirt, and that packed material is what stops a key seating properly. Dig it out completely before the key goes near it. A key bottomed into sludge rather than steel will round a plug on the first serious pull, and a rounded drain plug on a full gearbox is a genuinely bad position to be in.

The other difference is direction of care. A plug seals, so it is going back into a soft housing with a washer or a taper, and over-tightening it on the way back cracks castings and distorts sealing faces. Nip it up rather than heaving on it.

Fourteen millimetre cap screws exist too, on large machine frames, presses and structural plant, and the same key serves both.

Forged chrome vanadium, hardened and tempered.

Buyers are plant and machinery maintenance, agricultural and earthmoving workshops, hydraulic engineers, generator and compressor servicing, heavy vehicle shops, and dealers supplying industrial customers who need one large key rather than a set.

The catalogue name shows Harden's carton figure in brackets. This is one 14mm key. Tell us on 94 77 111 8880 what machine it is for and we will confirm the size before you travel. We deliver island-wide.