pliers [1]
Hand tools with two movable jaws of fixed or variable gaps, intended for gripping or clamping objects.
slip joint pliers 
Pliers with curved jaws and ending in a straight part, adjustable to two widths of opening.
curved jaw 
Jaw whose internal side is rounded for gripping or clamping a round object.
handle 
Long part that, in concert with its twin, exerts pressure to open or close the jaws.
slip joint 
Pliers’ articulating axle, which slides between two positions to change the jaws’ gap.