Diagonal pliers (or wire cutters or diagonal cutting pliers or diagonal cutters) are pliers intended for the cutting of wire (they are generally not used to grab or turn anything). The plane defined by the cutting edges of the jaws intersects the joint rivet at an angle or "on a diagonal", hence the name. Instead of using a shearing action as with scissors, they cut by indenting and wedging the wire apart. The jaw edges are ground to a symmetrical "V" shape; thus the two jaws can be visualized to form the letter "X", as seen end-on when fully occluded. The pliers are made of tempered steel with inductive heating and quenching often used to selectively harden the jaws.
Diags or Dikes (a portmanteau of "Diagonal CutterS" is pronounced "dikes") – as in the phrase "a pair of dikes" or "hand me those dikes" – is jargon used especially in the electrical industry, to describe diagonal pliers. Dike can also be used as a verb, such as in the idiom "when in doubt, dike it out".
In the United Kingdom and Ireland, diagonal pliers are commonly referred to as snips, and in Australia and Canada they are often referred to as side cutters.