Pliers

Several commonly types of pliers are shown below. 

Different types of pliers

Side cutting pliers are used principally for holding and bending thin materials or for cutting wire. Adjustable combination pliers have a slip joint that permits the jaws to be opened wider at the hinge for gripping large diameters. They are used principally for holding and bending flat or round stock. The various lengths and shapes of flat-nose, round-nose, and needle –nose or long –nose pliers make possible to bend or form metal into a variety of shapes, to hold objects in tight spots and to make delicate adjustments.

Needle-nose pliers are helpful when removing washer or nut from a place where it is hard to reach. They also make it easier to install and remove such a thing as valve spring retainer pin. They not of heavy construction, however, and should not be forced beyond their capacity. Their jaws are comparatively weak and easily broken or sprung.

Diagonal cutting pliers have short jaws with blades at a slight angle. The tool is valuable while removing and replacing cotters pins and can be used not only to cut the pins to the desired length but to spread the ends after the pins are in place. They are also handy for cutting the soft wire which is which is passed through small holes in nuts and bolts head to safety them, or prevent from working loose. When diagonal cutting pliers are used, the cut should be made with the throat of the jaws, not with the points, as the latter use would increase the tendency to spring the jaws apart. Once the jaws are sprung, it is difficult to cut fine wire. 

 Cautions:Avoid using pliers on hardened surface as such use dulls the teeth and causes pliers to loose their gripping power. Do not use pliers for loosening or tightening nuts, as the flats of the nut will become damaged.