A type 
	  of hammer with an iron head and an oak handle. The gennou is used 
	  to strike a chisel or plane, or to drive nails. The iron head has two striking 
	  faces; one is flat, and the other bulges out slightly in the center. This 
	  convex face is called kigoroshimen 木殺面 and is used, for example, 
	  to lightly tap the handle of a chisel in the last stage of driving a nail. 
	  Gennou are classified by the weight of the head: those with 650-750g 
	  heads are called, daigennou 大玄能; with 400-500g heads, chuugennou 
	  中玄能; and with 250g heads, shougennou 小玄能. The length of the gennou 
	  handle varies according to the weight of the head, but a length of about 
	  300mm is standard. The profile of the handle is rectangular at the blade 
	  entrance, (the expression gohira 五平 is sometimes used), but oval 
	  where it is held in the hand, giving an easy grip. 
	   |