Cutting tap and method of making same

Abstract

A method of making a cutting tap includes the steps of: grinding a blank to form a threaded body portion at an axially forward end of the cutting tap, grinding one or more flutes in the threaded body portion to form cutting edges; grinding the threaded body portion to form a first cutting thread and a second cutting thread, the first cutting thread at a first distance from the axially forward end of the cutting tap, and the second cutting thread at a second distance from the axially forward end of the cutting tap; and grinding a chamfer in the threaded body portion such that a thickness of a section of material removed from the second cutting thread is smaller than a thickness of a section of material removed from the first cutting thread during a tapping operation.

1 - 17 . (canceled) 
     
     
         18 . A method of making a cutting tap, comprising the steps of:
 grinding a blank to form a threaded body portion at an axially forward end of the cutting tap;   grinding one or more flutes in the threaded body portion to form cutting edges;   grinding the threaded body portion to form a first cutting thread and a second cutting thread, the first cutting thread at a first distance from the axially forward end of the cutting tap, and the second cutting thread at a second distance from the axially forward end of the cutting tap; and   grinding a chamfer in the threaded body portion such that a thickness of a section of material removed from the second cutting thread is smaller than a thickness of a section of material removed from the first cutting thread during a tapping operation.   
     
     
         19 . The method according to  claim 18 , wherein the chamfer is non-linear such that a peripheral surface of the first and second cutting threads is on a curved line. 
     
     
         20 . The method according to  claim 18 , wherein the chamfer is formed such that a chamfer angle of the second cutting thread is smaller than a chamfer angle of the first cutting thread.