Holder for a cutting tool for metalworking and a method for the production of a holder for a cutting tool

Abstract

There is disclosed a holder for a cutting tool and a method for the production of a cutting tool for metalworking that results in a holder body having increased fatigue strength at loads over 60% of the yield point in tension. The method and the tool are characterized in that the holder body of the tool is subjected to a hardening process resulting in deep hardening, and that the holder body then is subjected to a surface treatment resulting in a strain hardening of the surface in order to introduce compressive stresses in the surface zone of the holder body.

1 . Method for the production of a holder for a cutting tool for metalworking, comprising a holder body having one or more insert seats intended to receive a cutting insert, the holder body of the tool being made of steel, comprising: 
 deep hardening of at least a part of the holder body and then    surface treating at least a portion of this part of the holder body in order to introduce compressive stresses in the surface zone of the holder body.    
   
   
       2 . A method according to  claim 1 , comprising 
 deep hardening the entire holder body.    
   
   
       3 . A method according to  claim 1 , comprising 
 surface treating in and adjacent to the insert seats.    
   
   
       4 . A method according to  claim 1 , comprising 
 surface treating the entire holder body.    
   
   
       5 . A method according to  claim 1 , wherein said 
 surface treating is done by shot peening.    
   
   
       6 . A holder for a cutting tool for metalworking comprising a holder body having one or more insert seats intended to receive a cutting insert, the holder body being manufactured from steel, at least a part of the holder body is depth hardened, and at least a portion of the depth hardened portion has a strain hardened surface.  
   
   
       7 . A holder for a cutting tool of  claim 6 , wherein the holder body is a part of a drill having a hardness of at least 40 HRC.  
   
   
       8 . A holder for a cutting tool of  claim 6 , wherein the holder body is a part of a tool for milling or turning operations and has a hardness of at least 36 HRC measured at the surface thereof.  
   
   
       9 . A holder for a cutting tool of  claim 6 , wherein the surface has a random fine-pitted structure.  
   
   
       10 . A holder for a cutting tool of  claim 9 , wherein the surface has a random fine-pitted structure over the entire holder body.  
   
   
       11 . A holder for a cutting tool of  claim 9 , wherein the random fine-pitted structure is present in and adjacent to the insert seats.  
   
   
       12 . A holder for a cutting tool of  claim 9  wherein the random fine-pitted surface is produced by shot-peening.  
   
   
       13 . A holder for a cutting tool of  claim 7  wherein the drill has a hardness of at least 40 HRC throughout its entire cross-section.