In the fall of 2001, David W. Stewart successfully resolved a problem that had plagued the standard claw hammer
  from its conception.

  The problem was the claw hammer's inability to extract nails that were held fast in wood that had cured over many
  years. Until Mr. Stewart's invention the solution had been to place a block of wood under the heel of the hammer to
  act as a fulcrum, or to use a crowbar to extract the nail.

  Mr. Stewart's invention provides an 8 to 1 leverage (pulling) advantage over standard claw hammer. A block of wood
  or crowbar is no longer needed for extracting nails.