Most weapons come in many qualties, tulwars, & kukris are great examples of this. 
 
Some are  junk , some can also be  great pieces of weaponary or art. True masterpieces. 
 
As for tulwars they can have blades of any origin or type of steel in them, although I  must say quarter curved to a circle sounds rather nice to me!   
 
Thats sounds rather like a shamshir blade in a tulwar hilt. 
 
After all generaly its the shape of the hilt that decides the name tulwar. 
 
 
Spiral
		 
		
		
		
		
		
		
		
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