Powdered metal multi-lobular tooling and method of fabrication

Abstract

A tool made of powdered metal, such as a modified T15 HSS in powdered form, and having a multi-lobular end profile for punching multi-lobular recesses into workpieces, such as into the heads of fasteners. The tool is homogenous and contains only carbides which are relatively small, such as in the 1-4 micron range. Also provided is a method of fabricating such a tool. The method requires that a powdered metal bar is cut and then the cut piece is worked to provide the multi-lobular tool. The final part is theoretically 100% dense, as opposed to being only 95-98% dense as in metal injection molded parts. In use, the final part, due to how it is fabricated, has increased column strength and increased impact resistance.

1 . A method of fabricating a tool made of powdered metal, where the tool has a multi-lobular end profile for punching multi-lobular recesses into workpieces, said method comprising: providing a rod formed of powdered metal; cutting a predetermined length from the rod, said predetermined length defining a part; applying a chamfer to at least one end of the part; grinding an outside diameter of the part to a predetermined size; extruding a multi-lobular configuration on one end of the part; grinding an outside diameter of the part to a predetermined size; and forming the part to a predetermined length. 
     
     
         2 . A method as recited in  claim 1 , further comprising stress relieving the part in a heat treat furnace. 
     
     
         3 . A method as recited in  claim 1 , further comprising coining a trademark onto the part. 
     
     
         4 . A method as recited in  claim 1 , further comprising facing the part to a predetermined final length. 
     
     
         5 . A method as recited in  claim 1 , further comprising shaving a nose angle on the part. 
     
     
         6 . A method as recited in  claim 1 , further comprising heat treating the part to a predetermined hardness. 
     
     
         7 . A method as recited in  claim 5 , further comprising polishing the nose angle to desired finish. 
     
     
         8 . A method as recited in  claim 1 , wherein the step of cutting a predetermined length from the rod comprises cutting a predetermined length from a rod formed of high speed steel. 
     
     
         9 . A method as recited in  claim 1 , wherein the step of cutting a predetermined length from the rod comprises cutting a predetermined length from a rod formed of T15 high speed steel. 
     
     
         10 . A method as recited in  claim 1 , wherein the step of cutting a predetermined length from the rod comprises cutting a predetermined length from a rod formed of high speed steel which includes molybdenum. 
     
     
         11 . A method as recited in  claim 1 , wherein the step of cutting a predetermined length from the rod comprises cutting a predetermined length from a rod formed of T15 high speed steel which includes molybdenum. 
     
     
         12 . A method as recited in  claim 1 , wherein the step of applying a chamfer to at least one end of the part comprises applying a 47°/45° chamfer to both ends of the part. 
     
     
         13 . A method as recited in  claim 1 , wherein the step of extruding a multi-lobular configuration on one end of the part further comprises applying oil to the part and extruding the multi-lobular configuration in an extrusion die that is secured in a punch press.