Technology and our changing world high Technology

THE FORGING PROCESS
Drawing
Drawing is a way of working a piece so that it increases in length, width, or both, and decreases in thickness. Hammer toe metal over toe flat face of toe anvil. When a long piece of metal must be drawn out(increased in length and width), heat and work one section at a time. Always direct toe blows toward toeheavier partof toe metal. Work toe metal in “steps”.

Upsetting

Upsetting is the reverse of drawing. In upsetting the length is decreased and the thickness is increased. There are several methods used for upsetting. For shortpieces, the metal can beheld uprighton the anvil and the end struck with ahammer. Thehead of abolt is formed in this way.

Bending

Hot bending of squares and angles should be done ova' the face of lhe anvil. Large curved bards are made over the rounded horn of the anvil. With practice you can learn to forge metal using the anvil, a vise, and the different hammers.


Heat Treating
Suppose you have turned a punch on a lathe or forged a chisel. To make the tool strong, it must be hardened and tempered. Or perhaps you would like to make a scraper from an old metal file. Before the file can be reworked, it must be softened, or annealed. Hardening, tempering, and annealing we heat-treating processes.
Heat treating is best to follow in heat treating a cold chisel forged from tool steel.
First, anneal the metal by heating it until it is cherry red. Then cool it in the air. This softens the metal and relieves the strains of forging. File the metal smooth and polish it with abrasive cloth and oil.
Next, harden the metal by reheating about 1 ” of its tip until it is cherry red. This heats the metal to the critical temperature. Plunge the metal quickly into water, moving it with a circular motion. Test the hardness with a file. If the file nicks the chisel, anneal and harden again. Hardness testing machines are also used.
Finally, polish lhe tip with abrasive cloth. Thor temper the metal by applying heat about 1” above the tip. When the temper color-brown, in this case -reaches the tip, plunge the tool into water. Tempering reduces lhe brittleness of the piece.