In return for shipping some 2x2x6" crotch walnut blocks to Romania a blacksmith in that country made these two hidden tang blades for me. I used dense very slow growing Chestnut Oak saplings for the handles. I cut saplings that are growing under large trees and sometimes they can be 15 years old and only 1 1/2" diameter.
The one on top is five layers of steel and it was made for someone with a very large hand. The blade is 1/4" thick at the handle and it tapers to the point. The bottom one(sold) is 3 layers. The steel in the center is very hard tool steel, this becomes the edge. The outer layers are somewhat softer steels to provide a bit of flex. Think of San Mai as a sandwich.
The following site talks about San Mai in more detail:
http://www.koboldpress.com/k/front-page12050.php#.UkGYUX9Lb1UThe two small knives on the left of the next photo are not San Mai.
At the top left is a small skinner with forged A2 steel blade and whitetail antler for the handle.
At the bottom left is a skinner I made using a piece of Nicholson file for the blade and blackened Dogwood for the handle.