Cutting bit adapted to cut metal and wood and associated method
A cutting bit adapted to cut wood or metal is disclosed. The cutting bit is prepared by a process which includes the step of performing a forming operation on a metal blank so as to create a formed metal part that includes (i) a shaft having a polygonal shaped drive surface and defining an axis, (ii) a body having a proximal end and a distal end, the proximal end of the body being attached to the shaft, the body further having a first shoulder and a second shoulder at the distal end thereof, the first shoulder defining a first cutting edge segment, and the second shoulder defining a second cutting edge segment, the axis extending between the first cutting edge segment and the second cutting edge segment, (iii) a central cutting member extending from the body so that the central cutting member is aligned with the axis, (iv) a first cutting spur extending from the distal end of the body, the first cutting edge segment being interposed between the first cutting spur and the axis, and (v) a second cutting spur extending from the distal end of the body, the second cutting edge segment being interposed between the second cutting spur and the axis. The process of preparing the cutting bit further includes the step of performing a carburization operation on the formed metal part after the first step so as to create the cutting bit. The cutting bit is particularly useful in performing a drilling operation on a metal construction wall stud to form a hole therein.
1. A cutting bit adapted to cut wood or metal, said cutting bit comprising:
a shaft defining a shaft axis;
a body portion extending distally from the shaft along the shaft axis;
a first cutting edge segment located at a distal end of the body portion;
a second cutting edge segment located at a distal end of the body portion, the shaft axis extending between the first cutting edge segment and the second cutting edge segment;
a central cutting member extending distally from the body along the shaft axis;
a first cutting spur extending distally from the body at a location outwardly of the first cutting edge segment; and
a second cutting spur extending distally from the body at a location outwardly of the second cutting edge segment, wherein:
the first cutting edge segment and the second cutting edge segment define a cutting edge axis that intersects the shaft axis at a first shaft axis location;
when the first cutting spur is projected onto the shaft axis, a projected distal end of the first cutting spur is at a second shaft axis location that is spaced apart from the first shaft axis location by a distance that is greater than a thickness of a commonly sized work piece;
the central cutting member comprises a substantially cylindrical base and a tip portion; and
the tip portion includes a lip relief.
2. The cutting bit of claim 1 , wherein the base comprises at least one helical thread.
3. The cutting bit of claim 1 , wherein the second shaft axis location is spaced apart from the first shaft axis location by a distance that is greater than about 0.040 inches.
4. The cutting bit of claim 3 , wherein the second shaft axis location is spaced apart from the first shaft axis location by a distance that is greater than about 0.080 inches.
5. The cutting bit of claim 1 wherein the central cutting member, the first cutting spur, and the second cutting spur have a hardness of at least about 55 RC.