The Hammer Head
Although a hammer head appears relatively simple in its construction, it's only a single piece of metal after all, there are several technical terms for the parts of the hammer that we need to understand before looking at the hammer head in more detail:
The claw is the two pronged section at the opposite end of the head to the face that is used for gripping and removing nails. Not all hammers have a claw.
The striking face is called a pein, probably because that's what you get a lot of when you hit your thumb! For the sake of simplicity, we'll call it the face from now on.
The chamfer is the angled area around the face. If the material being hit is very hard there is a chance that a glancing blow could chip a bit off the work piece and cause injury or damage; the chamfer greatly reduces this risk.
The head of any hammer should be made from drop forged steel. Drop forging is where a piece of steel is made red hot and then a large weight is dropped onto it, bashing it into a die (a mould with the shape of the head cut into it).
After this it is put into a special machine that cuts off the excess material. This process is known as cropping (see the image on the left).
The reason for using this drop forging technique is that the grain structure of the steels follows the contour of the head. This makes it much stronger and less prone to chipping than if it were cast (a process where molten metal is poured into a mould) - All C.K and Avit hammers have drop forged heads.
After forging and as the steel cools and shrinks, it creates some internal stress in the steel. This is addressed by heat treating the hammer head, which we'll look at next.