pliers [2]
Hand tools with two movable jaws of fixed or variable gaps, intended for gripping or clamping objects.
rib joint pliers 
Pliers with straight jaws, adjustable to several gap positions.
handle 
Long part that, in concert with its twin, exerts pressure to open or close the jaws.
bolt 
Metal plug ending in a head and threaded for screwing into a nut; it forms the pliers’ axle of articulation.
nut 
Hollow cylinder of metal whose lining is threaded to screw onto a corresponding bolt.
straight jaw 
Jaw whose interior side is rectilinear for grasping or clamping a flat, square or many-sided object.
adjustable channel 
Set of notches that receive the bolt to change the jaws’ gap.