Patent ID: 8592711

Claim:
A self sharpening cutting edge formed from the process of: shaping a titanium alloy shank having a Rockwell C hardness less than 65 to include a first bevel extending from a spine tapering to a distal end along a first side of said shank to an edge and a second bevel extending from said edge to a spine along a second side of said shank; drawing said first bevel of said metal shank along a spark deposition tool post coupled to an electronic charge generator, said spark deposition tool post having at least one carbide guide constructed and arranged to maintain spacing of said first bevel a distance from an electrode, depositing a layer of carbide based electrode material from said electrode on said first bevel by pulsed electric discharge from said spark generation tool post so that said layer is a titanium alloy, said layer of electrode material having a material deposit of about 0.0002-0.0003 inches when said first bevel has an angle of between 10-15 degrees, said layer of electrode having a material deposit of about 0.0003-0.0004 inches when said first bevel has an angle of between 15-20 degrees, said layer of electrode material having a material deposit of about 0.0004-0.0005 inches when said first bevel has an angle of between 20-25 degrees, controlling said material deposit by an amount of electrical current directed to said spark deposition tool post layer at said rate of application forming a zone of differential between said first bevel and said second bevel; wherein said zone of differential wears before said first bevel allowing said edge to remain sharp.