NABTEB

Explain the term “weld defect” – NABTEB QUESTION

ANSWER A weld defect is an imperfection on the weld which may lead to failure of the joint under service…

4 years ago

Explain the reason for heat treating cast iron before welding. – NABTEB QUESTION

ANSWER Cast iron is very brittle and this makes it difficult to weld unlike steel. Heat treatment is therefore required.…

4 years ago

Explain the following terms (i) Ductility (ii) Malleability (iii) Hardness (iv) Tenacity – NABTEB QUESTION

(i) Ductility: This is the ability of material to be drawn into thin wire without fracture e.g. copper, aluminum, e.t.c.…

4 years ago

Explain the flame used when brazing – NABTEB QUESTION

ANSWER Neutral flame is generally used for brazing. Oxidizing flame may be used when present metal or filler rod contains…

4 years ago

State THREE functions of flux in hard soldering? – NABTEB QUESTION

ANSWER (i) To dissolve any oxide that is present on metal surface. (ii) To prevent corrosion or oxidation by excluding…

4 years ago

State and explain THREE advantages of a D.C. machine over an A.C. machine. – NABTEB QUESTION

(i) D.C. machines can be used to weld non-ferrous metals. (ii) Bare wire electrodes can be carefully used. (iii) It…

4 years ago

Differentiate BETWEEN Destructive tests and Non-destructive tests – NABTEB QUESTION

Destructive tests are those tests carried out with the joint destroyed by bending, cutting or application of chemical e.g. microscopic,…

4 years ago

Name TWO ways in which excessive spatter can be controlled. – NABTEB QUESTION

(i) The current should be reduced to normal. (ii) A wet electrode should be dried especially in the oven. (iii)…

4 years ago

State THREE major causes of excessive spatter. – NABTEB QUESTION

Excessive spatter may occur in arc welding as a result of: (i) Too high welding current used (ii) Wet electrode…

4 years ago

Describe TWO methods of how a non-ferrous metal can be heat treated. – NABTEB QUESTION

(i) A non-ferrous metal (aluminum) can be heat treated by annealing after cold working which increases hardness. This can be…

4 years ago