At some point in their lives everyone has used a hammer. And if not a hammer, something hard has been used to hit some thing softer to flatten it out or change its shape. In its most basic form, that is what a blacksmith does with this hammer.
Hammering a piece of hard cold metal into a new shape is time consuming, requires a lot of effort and may not be successful. Also while metals may be hard, they may also be brittle and applying hammer force to them may cause cracks and breaks. This is why a blacksmith works only with malleable material like wrought iron or mild steel. And before he tries to hammer it into shape, he heats it up until it reaches a consistency that allow him to hammer it into shape the shape he wants without damaging the metal.
Once the metal is heated in the forge, it is placed on an anvil and the blacksmith uses a variety of different hammers to shape the metal as he wants. In general the largest hammers, with the biggest and heaviest heads are used to create the basic shape and then smaller and lighter hammers are used to create the finer shapes and finishes. The blacksmith’s hammer is his main working tool in shaping metal and he has be strong to apply the force to the hammer blow, accurate in hitting the exact spot, knowledgeable about which hammer to use when and also be able to work fast – from the time the metal leaves the forge it starts cooling off and within a short time it will have cooled to the extent that shaping it properly become impossible.
There are many different application of the blacksmith’s hammer in metal working.
· Firstly is the one everyone knows – hammering the hot iron on various parts of the metal with differing amounts of force and from different angles to form a shape. This can include bending it to from a curve or create a corner of a specific shape. The hammer is also used hammer on the flat sheet of iron to make it thinner and create more surface area. This is known as “drawing” the metal. The reverse of this is “upsetting” where the blacksmith hammers on the sides of the iron piece to make is shorter and thicker.
· The hammer is used along with a “punch” to literally punch holes in the metal. The punch is placed over the spot where the hole is to be made and then hit with the hammer to create the hole.
· The hammer is used along with a chisel to either cut or split the iron. This sharp end is held against the surface of the metal and when the opposite end is hit with the hammer, it cuts through the metal. The chisel can also be used against the end of the iron piece to split it into a Y shape.
· The hammer is also used to pound in rivets to join two pieces of metal together.
· And finally, when if two pieces of metal are heated to almost the melting point and then the then hammered so that they meld into one piece; that is called hammer welding.