All Pro-Line Tools are individually made from high carbon knife quality steel that has been heat treated and quenched in oil to give the blades maximum hardness and durability. Because high carbon steel takes and holds a much sharper edge than stainless, they last longer against even highly-grogged clays and plaster. Handles are retained by brass ferrules firmly set with industrial adhesive. In addition, each handle is immersed in an oil resin bath to seal the handle against water damage and prolong the life of the tools.