Heating

Question 1

Oxy-acetylene definition and uses

Answer 1

mixture of oxygen and acetylene burns in a concentrated flame and when in contact with steel melts it and filler rod of same material is used to complete the joint
Uses - sheet, tubes, forging and shaping metal

Question 2

MIG welding definition and uses

Answer 2

electric arc welding where using an electric current an arc is struck between the work and the electrode. The filler is a thin wire that is fed into the joint. An inert gas (argon) flows over the area so oxygen is kept away.
Uses - for metals that can’t e gas welded (aluminium)

Question 3

Brazing definition and uses

Answer 3

joining of 2 materials using brazing torch. But materials must be cleaned with emery cloth, a flux is applied which stops oxidation of the metal and breaks surface tension so molten spelter can flow.
Uses - joining mild steel to mild steel

Question 4

Hard soldering definition and uses

Answer 4

similar to brazing, a flux is needed and a torch is used
Uses - jewellery, copper joining

Question 5

Soft soldering definition and uses

Answer 5

base metal not melted but solder filler material bonds the parts together, soldering iron used. Makes airtight or watertight joints.
Uses - circuitry