Kasumi knives are made of 33 layers of folded steel. Only the middle layer acts as the cutting edge, and it is made using V-Gold No. 10 stainless steel. Each Kasumi knife blade is a high carbon stainless steel with cobalt, manganese, molybdenum and vanadium for added durability and ease of sharpening. V-Gold No. 10 is a high quality steel developed exclusively for knives and scissors. The addition of cobalt to this steel requires special tempering in order to maximize the full benefit of this steel. Sumikama's technique for this special tempering is a closely guarded secret. Each Kasumi knife has a laminated pakka wood handle secured with stainless steel rivets. A beautiful knife that will provide a lifetime of performance.
The edge on a Kasumi knife is beveled like a western style knife. However, the bevel is much larger than the bevel on a European or American brand. This larger bevel creates a sharper edge. Kasumi knives do not have a bolster. They do have a stainless steel ferrule that is forge welded to the blade to ensure that food particles do not become trapped between the blade and the handle. They also have a full tang. The handle is made from multiple layers of wood impregnated with a plastic resin. The handle is riveted to the tang.