Irwin-Industrial Tool Company

American Saw & Mfg. Company, Inc.

American Saw & Manufacturing Company

Brian K Douglas

William B Korb

Kenneth Hall

Dayananda Sukadhare

Gary F Scott

Marcelo Oliveira

A composite utility knife blade and method of making such a blade involves butt joining a tool steel wire to a front edge of an alloy steel backing strip. The wire is electron beam welded to the backing strip to form a composite strip defining a first metal portion formed by the alloy steel backing strip, a second metal portion formed by the tool steel wire, and a weld region joining the first and second metal portions. The composite strip is then annealed, and the annealed strip is straightened to eliminate any camber therein. The annealed composite strip is then hardened such that the first metal portion defines a surface hardness within the range of approximately 38 Rc to approximately 52 Rc, and the second metal portion defines a surface hardness within the range of approximately 60 Rc to approximately 57 Rc.

Methods of making utility knife blades

A composite utility knife blade and method of making such a blade involves butt joining a tool steel wire to a front edge of an alloy steel backing strip. The wire is electron beam welded to the backing strip to form a composite strip defining a first metal portion formed by the alloy steel backing strip, a second metal portion formed by the tool steel wire, and a weld region joining the first and second metal portions. The composite strip is annealed and hardened such that the first metal portion defines a surface hardness within the range of approximately 38 Rc to approximately 52 Rc, and the second metal portion defines a surface hardness within the range of approximately 60 Rc to approximately 75 Rc. The hardened strip is then tempered, quenched, surface treated to form a sharpened cutting edge, scored, and separated into a plurality of blades.

Composite utility knife blade, and method of making such a blade

A composite utility blade and method of making such a blade involves butt joining a high speed or tool steel wire to a front edge of an alloy steel backing strip. The wire defines a predetermined cross-sectional shape that substantially corresponds to the cross-sectional shape of the cutting edge of the blade. The wire is electron beam welded to the backing strip to form a composite strip defining a first metal portion formed by the alloy steel backing strip, a second metal portion formed by the high speed or tool steel wire, and a weld region joining the first and second metal portions. The composite strip is then annealed, and the annealed strip is straightened to eliminate any camber therein. The annealed composite strip is then hardened such that the first metal portion defines a first surface hardness and the second metal portion defines a second surface hardness greater than the first surface hardness. The hardened strip is then subjected to tempering and quenching cycles, and facets are formed on the edge of the second metal portion to form a straight, tool steel cutting edge. The composite strip is then scored at axially spaced locations to form a plurality of score lines, and the plurality of score lines define a plurality of blade sections there between. The cutting edge may be coated with AlTiN, TiN, or an inner coating of AlTiN and an outer coating of TiN.

Composite utility blade, and method of making such a blade

Method of making a composite utility blade

A sheet metal hole cutter has a cap plate defining a substantially circular peripheral groove and an annular shelf extending radially outwardly from the peripheral groove. An elongated band forming an approximately circular shape with opposite ends of the band contacting each other defines a base edge received within the circular peripheral groove in an abutting relationship with an inner edge of the groove. The band defines an axial depth of about &#xbd; of an inch or less, and an outer diameter within the range of about 9/16 of an inch through about 6 inches. A weld region fixedly secures the base edge of the band to the cap plate. The annular shelf of the cap plate extends radially outwardly from the base edge of the band and defines a radial depth of at least approximately 1/16 of an inch in order to prevent over-feeding of the hole cutter through a work piece. A plurality of teeth are disposed along a cutting edge of the band, and each tooth defines a cutting surface extending between an outer edge and an inner edge of the tooth. Each cutting surface is oriented at an acute angle relative to the plane of the cap plate such that the outer edge of the respective tooth is spaced further away from the cap plate than the inner edge to thereby preferentially cut the work piece with the outer edge and create a substantially burr-free hole in the work piece.

Sheet metal hole cutter

Composite utility knife blade

Hacksaw

Growing community of inventors

Enfield, CT, United States of America

Brian K Douglas