The Tezuchi or Japanese Bladesmithing Hammer.
The head itself is tapering from 40x40mm or 1 1/2x1 1/2" to 35x35mm or 1 3/8x1 3/8" enabling easier and more precise blows because of the reduced surface area contact.
The face is gently crowned and set at and angle same for the handle just like the original hammers from Japan.
The head itself weighs 2.5lb or 1150g handforged out of 1045 tool IRON
The striking face is expertly hardened and tempered enabling years and years of harsh use but the body of the hammer is left soft to absorb shock.
Handcarved 38cm/15" Ash handle that is oval in the cross section enabling perfect control over the hammer then changing shape to a rectangular profile as it goes into the hammer eye portion.
The handle is treated with boiled linseed oil