Each handle is ground and fit from straight grain aged hickory. The hammer handle is glued using a modern Polyurethane adhesive. This has the advantage of being able to flex during humidity and temperature changes which should give you many years of trouble free performance without the head loosening. You should always take the time to fit the handle to your hand.
Like all hand forged items each is unique and the overall weight and shape will vary slightly.
We use 1045 steel in our hammers, Rockwell 50-55 hardness.