Despite their occasional usefulness—in some cases serving a purpose no other tool can fill—pliers get little respect in the automotive tool world. Possibly the only tool more scorned is the adjustable (or “monkey”) wrench with its sloppy fit on almost any fastener.
Pliers can at least grip properly; their main drawback is the tendency of the teeth to scar the flats of nuts and bolts, and to slip and subsequently round off fasteners if not gripped tightly enough to risk that scarring.
Enter the Knipex parallel-jaw pliers, or as the company refers to them, pliers wrench.
The lower jaw of the Knipex PJ pliers (my nickname) does not pivot about a central axle; instead it moves straight up and down in a track, and is adjusted with a separate handle on a pivot. The coarse adjustment is accomplished by sliding the handle up or down a toothed track, and the overall range is impressive: The compact 180mm model shown here can adjust its grasp from zero—i.e. gripping a piece of paper or sheet metal—up to a full 1 1/2 inches or 40mm. That means a pair of these could, in a pinch, substitute for a full ratchet/socket and wrench set from 3 or 4mm all the way up to 24mm or so (beyond that their leverage might be insufficient). Add the 250mm model for even more versatility.
One advantage of using the PJ pliers to, say, hold a nut while one unscrews a bolt from it, is that you actually grip the nut, which you cannot do with a standard wrench. This would be extremely useful in tight spaces were dropping the nut might mean a five-minute search in the bowels of the engine compartment—or the mud underneath. Likewise, when trying to thread a nut onto a bolt in a tight space you can retain a firm grip on it. Like all Knipex (pronounced “kineepex,” incidentally) pliers, due to the superior steel used the jaws are quite narrow, further enhancing their usefulness.
Disadvantages? The lack of teeth renders the PJ pliers useless at gripping round things—axles, the shaft of a bolt, etc.—which is why I also carry the company’s excellent standard sliding-jaw pliers. A very useful addition to a home or field tool kit.
Knipex is here.