Diagonal cutting pliers use lever action to create enough force to cut through small pieces of metal.
The force applied by your hand as you squeeze the handles together is magnified through the pivot point and causes the jaws to move together. Because the cutting point is closer to the pivot point than the handles, the force of the blades on the wire is much greater than the force being applied to the handles.
The force applied to the wire (or ‘cutting capacity’) can be increased by increasing the distance from the pivot point that the handles are squeezed. This can be achieved by the user squeezing at the tips of the handles or the manufacturer lengthening the levers (handles).
Cutting capacity at the tip of the diagonal cutting pliers blades can be increased by the manufacturer shortening the length of the jaws.
The blades of diagonal cutting pliers are in line with each other and cut by squeezing the metal and pushing it apart.