Combination Spanner (12mm)

The open jaw has one ability that nothing else in a toolkit can match: it goes on from the side. A ring has to be dropped over the end of a fastener, and a socket has to be dropped over it and needs clear depth above it as well. Neither of those is possible when the nut sits on a bolt with a pipe, a rod, a hose, a cable or a bracket running through or past it. Brake and fuel line unions, hydraulic fittings, cable glands, pipe clips, turnbuckles and tie rods are all fastenings you can only get at from the side, and the open jaw is the only tool that will do it.

The jaws are also set at an angle to the handle rather than square to it, and that is deliberate too. It means that when you run out of swing, you can lift the spanner off, flip it over, and put it back on the same nut in a different position, gaining a fresh bite without needing any more room than you had. Most people do this by instinct without ever noticing why it works.

What the open jaw cannot do is hold on under heavy load. Gripping only two of the six faces, it spreads slightly as you pull, and once it spreads it starts to ride up the faces towards the corners. That is why the sensible habit is to leave the open end for access and for speed, and to give the ring end anything that is genuinely tight.

Twelve millimetre heads are widespread on vehicle and motorcycle assemblies, machinery mountings, brackets and frames, and general fabrication.

Carbon steel, forged, hardened and tempered, with satin matt chrome plating for corrosion resistance.

Buyers are vehicle and motorcycle workshops, plumbers and pipefitters, hydraulic engineers, fabricators, maintenance fitters and hardware shops.

Ask us on 94 77 111 8880 about singles or the fifteen piece set. We deliver island-wide, with trade prices for dealers.