Design:Forming and Sharping Metal
Metals can be formed or shaped in three main ways — heating， cold-forming and milling. Hot forming is used for shaping metals such as iron and steel. However， there are many alloys that would be damaged by the heat. Metals which have the ability to stretch permanently are ductile， and can be stretched or drawn when cold. High carbon steels like cast-iron are hard and brittle and cannot be stretched. Milling and cutting can also be used to shape metals.
- Added：2006
- Country：Australia
- Duration：22
- Time of update：2011/8/16 11:17:10