Shear knife
A metal shearing tool demonstrating improved fatigue life having a body; an edge of the body having a first surface and a second surface; a cutting surface disposed between the first surface and the second surface. The edge has at least one of a curved profile surface, a radiused cutting surface, and a substantial absence of finish marks substantially parallel with the cutting surface on all surfaces of the edge.
1. A metal shearing tool comprising:
a body;
an edge of the body having a first surface and a second surface;
a cutting surface disposed between the first surface and the second surface;
wherein the edge has at least one of a curved profile, a radius, and a substantial absence of finish marks substantially parallel with the cutting surface; and
wherein the metal shearing tool demonstrates improved fatigue life of at least 130% compared to the same metal shearing tool not having at least one of a curved profile, a radius, and a substantial absence of finish marks substantially parallel with the cutting surface.
2. The metal shearing tool of claim 1 , wherein the edge has at least two of a curved profile, a radius, and a substantial absence of finish marks substantially parallel with the cutting surface.
3. The metal shearing tool of claim 2 , wherein the edge has a curved profile, and a radius.
4. The metal shearing tool of claim 2 , wherein the edge has a curved profile, and a substantial absence of finish marks substantially parallel with the cutting surface.
5. The metal shearing tool of claim 2 , wherein the edge has a radius, and a substantial absence of finish marks substantially parallel with the cutting surface.
6. The metal shearing tool of claim 2 , wherein the edge has a curved profile, a radius, and a substantial absence of finish marks substantially parallel with the cutting surface.
7. The metal shearing tool according to any one of claim 1 , 2 , 3 , 4 , 5 or 6 , wherein the metal shearing tool demonstrates improved fatigue life of at least 200% compared to the same metal shearing tool not having at least one of a curved profile, a radius, and a substantial absence of finish marks substantially parallel with the cutting surface.
8. The metal shearing tool according to any one of claim 1 , 2 , 3 , 4 , 5 or 6 , wherein the curved profile is a convex curved profile.
9. The metal shearing tool according to claim 7 , wherein the curved profile is a convex curved profile.