The body of these knipex locking pliers is made from heavy duty high strength spring steel with inserted jaws made of chrome vanadium steel that has been drop forged for added strength and longer lasting durability these 41 04 250 pliers are a heavy duty model with wire cutter and have a spring action for ease of clamping and un clamping they have a high clamping strength due to the elbow lever action with an adjustment screw for a more secure grip and a release lever for single handed operation