Abstract: An expansion tool having a resilient wedge held in the inner face of an expandable jaw for engaging a ram tongue to expand the jaw. Each resilient wedge has a surface which has a low coefficient of friction, is self-lubricating and which does not bind with the surface of the tongue at high pressure, is angled to repeatedly engage the tongue and communicate great pressure to the jaws without the use of breakable or moving parts in the jaws, is comprised of a material resilient enough and is properly angled to cause the tongue to disengage when the pressure is released, and is hard, dense, and resilient enough to repeatedly withstand great pressure without breaking.