Method of making a composite utility blade

A composite utility knife blade, comprising:

• a back edge, a cutting edge located on an opposite side of the blade relative to the back edge, and two side edges located on opposite sides of the blade relative to each other and extending between the back and cutting edges of the blade, wherein the back, cutting and side edges of the blade define an approximately trapezoidal peripheral configuration;
• first means for forming a wear-resistant cutting edge defining a hardness within the range of approximately 60 Rc to approximately 75 Rc and extending from approximately one side edge to the other side edge;
• second means for forming a spring-like backing to the first means and defining a hardness within the range of approximately 38 Rc to approximately 52 Rc, said second means extending between the back edge and the first means and extending from approximately one side edge to the other side edge;
• and
• a weld region joining the first and second means and extending from approximately one side edge to the other side edge of the blade.

A method of making composite utility knife blades, wherein each blade comprises a back edge, a cutting edge located on an opposite side of the blade relative to the back edge, and two side edges located on opposite sides of the blade relative to each other and extending between the back and cutting edges of the blade, wherein the back, cutting and side edges of the blade define an approximately trapezoidal peripheral configuration;

• first and second metal portions, wherein the first metal portion forms a spring-like backing extending between the back edge and the first metal portion and further extending from approximately one side edge to the other side edge, and the second metal portion defines the cutting edge and extends from approximately one side edge to the other side edge;
• and a weld region joining the first and second metal portions and extending from approximately one side edge to the other side edge of the blade, the method comprising the steps of:
• providing an elongated wire formed of wear-resistant steel, and an elongated backing strip formed of steel and defining an approximately planar upper side, an approximately planar lower side, and opposing back and front edges extending between the upper and lower sides;
• butt joining the wire to the front edge of the backing strip;
• applying thermal energy to the interface between the wire and backing strip to weld the wire to the backing strip and, in turn, forming a composite strip defining a first metal portion formed by the steel backing strip, a second metal portion formed by the wear-resistant steel wire, and a weld region joining the first and second metal portions;
• annealing the composite strip;
• straightening the annealed composite strip;
• forming a plurality of notches axially spaced relative to each other along the back edge of the first metal portion of the annealed composite strip;
• hardening the annealed composite strip;
• tempering the hardened composite strip;
• quenching the hardened composite strip;
• forming at least one facet into the second metal portion and, in turn, forming an approximately straight wear-resistant steel cutting edge along the side of the composite strip opposite the back edge of the first metal portion;
• and
• die cutting at least one of the first and second metal portions along shear lines axially spaced relative to each other, wherein each shear line is oriented at an acute angle relative to the back edge of the first metal portion and at least one notch is located between adjacent shear lines, to thereby form a plurality of utility knife blades from the composite strip, wherein each utility knife blade defines an approximately trapezoidal peripheral configuration and at least one notch formed in the back edge thereof.