Thermit welding is a welding process that employs molten metal to permanently join the conductors.
The process employs an exothermic reaction of a thermite composition to heat the metal, and requires no external source of heat or current.
Thermit welding is often used in replacing broken gear teeth, repairing broken shears and joining rails, truck frames and locomotive frames etc.
Materials are limited to ductile materials because the threads are cold formed. .
Also, materials with good deformation characteristics are necessary for rolling; these materials include softer (more ductile) metals and exclude brittle materials, such as cast iron.
When a pattern is made in three parts, the ________ is known as a drag.
Materials used. Typically, materials used for pattern making are wood, metal or plastics. Wax and Plaster of Paris are also used,
Sugar pine is the most commonly used material for patterns, primarily because it is soft, light, and easy to work