Well since I am making hammers I decided to make it a set of 3.
This one is the big boy and can do the heavy stuff in the shop.
The head weighs in at 40 ounces and is 4 1/8" long with a diameter of 1.34 inches.
The handle is 10 3/4" long and 1" in diameter. The head attaching thread is 5/8-11.
(still waiting for my 5/8-11 bottom tap to finish the thread in the head)
The cap is threaded 3/8-16 and provides ample room for storage in the handle.
The steel is all just some hot rolled I had in the shop.