Golf club

Abstract

At least a part of a head portion of a golf club consists of stainless steel containing throughout 0.1% or more to 0.3% or less by weight of nitrogen. Further, at least a part of the head portion consists of a corrosion-resistant metal having a yield strength of 0.2% of 350 MPa or more to 600 MPa or less, a tensile strength of 500 MPa or more to 800 MPa or less and an elongation after fracture of 40% or more to 60% or less.

What is claimed is:  
     
         1 . A golf club comprising a head portion, wherein 
 at least a part of said head portion consists of stainless steel containing throughout at least 0.1% by weight to at most 0.3% by weight of nitrogen.    
     
     
         2 . The golf club according to  claim 1 , wherein 
 said stainless steel includes at most 0.08% by weight of carbon, at most 1.00% by weight of silicon, at most 2.5% by weight of manganese, at most 0.045% by weight of phosphorus, at most 0.03% by weight of sulfur, at most 0.15% by weight of niobium, at least 18% by weight to at most 20% by weight of chromium, and at least 7% by weight to at most 10.5% by weight of nickel, with the remainder consisting of iron and inevitable impurity.    
     
     
         3 . The golf club according to  claim 1 , wherein 
 said head portion has a face portion and a neck portion, and at least one of said face portion and said neck portion consists of said stainless steel.    
     
     
         4 . The golf club according to  claim 3 , wherein 
 thickness of a peripheral portion of said face portion is made smaller than thickness of a center portion of said face portion.    
     
     
         5 . The golf club according to  claim 1 , wherein 
 said head portion has a hollow structure and has a face portion consisting of said stainless steel, and    thickness of said face portion is at least 1 mm to at most 2.5 mm.    
     
     
         6 . The golf club according to  claim 5 , wherein 
 thickness of a peripheral portion of said face portion is made smaller than thickness of a center portion of said face portion.    
     
     
         7 . The golf club according to  claim 3 , wherein 
 said neck portion has an outer diameter of at least 8.5 mm to at most 12.5 mm and an inner diameter of at least 9 mm to at most 10 mm, and    said neck portion has a length of at least 30 mm to at most 80 mm.    
     
     
         8 . A golf club comprising a head portion, wherein 
 at least a part of said head portion consists of a corrosion-resistant material having a yield strength of 0.2% of at least 350 MPa to at most 600 MPa, a tensile strength of at least 500 MPa to at most 800 MPa and an elongation after fracture of at least 40% to at most 60%.    
     
     
         9 . The golf club according to  claim 8 , wherein 
 said yield strength of 0.2% is at least 400 MPa to at most 600 MPa, and said tensile strength is at least 600 MPa to at most 800 MPa.