Stainless steel forstner bit

Abstract

A corrosion resistant and durable forstner bit is formed from stainless steel using an investment casting process.

What is claimed is:  
     
         1 . A method of manufacturing a forstner bit comprising: 
 making a wax pattern of a forstner bit;    dipping said wax pattern in a refractory slurry to coat the wax pattern;    rolling the coated wax pattern in sand;    drying the coated and rolled wax pattern;    repeating said steps of dipping, rolling and drying until a prescribed coating thickness is achieved;    placing the entire coated pattern in a heated environment to melt away the wax, thereby to produce a mold ready for receiving molten material;    pouring molten stainless steel into said mold;    cooling the stainless steel; and    breaking away the casing to reveal the molded forstner bit.    
     
     
         2 . A method of casting as in  claim 1 , wherein said step of dipping in a slurry comprises dipping in a mixture of a binder and a refractory.  
     
     
         3 . A method of casting as in  claim 1 , comprising the step of preheating said mold before the molten stainless steel is poured.  
     
     
         4 . A method of casting as in  claim 1 , comprising the step of heating said mold to a firing temperature for firing said mold.  
     
     
         5 . A method as in  claim 1 , wherein said step of pouring stainless steel comprises pouring  416  stainless steel.  
     
     
         6 . A stainless steel forstner bit formed by the process of  claim 1 .  
     
     
         7 . A method of fabricating a forstner bit comprising: 
 fabricating a wax model of a forstner bit body, said wax model substantially representing a periphery of the bit body;    forming a mold from said wax model by applying a refractory mold material to external surfaces of said model and hardening said refractory mold material;    removing said wax model from said mold;    pouring molten stainless steel into at least one cavity of the resultant mold to form a bit body substantially corresponding in configuration and size to said wax model.    
     
     
         8 . A method as in  claim 7 , wherein said step of removing comprises heating said mold.  
     
     
         9 . A method as in  claim 7 , comprising the step of preheating said mold before the molten stainless steel is poured.  
     
     
         10 . A method as in  claim 7 , comprising the step of heating said mold to a firing temperature for firing said mold.  
     
     
         11 . A method as in  claim 7 , wherein said step of pouring stainless steel comprises pouring 416 stainless steel.  
     
     
         12 . A stainless steel forstner bit formed by the process of  claim 7.