NABTEB QUESTIONS - Page 51 of 119

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 being used (iii) Dirty metal surface e.g. Oil, grease.

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

by Sunday | Oct 2 | NABTEB QUESTIONS

(i) A non-ferrous metal (aluminum) can be heat treated by annealing after cold working which increases hardness. This can be done by heating with blow pipe and smeared with soap or match stick rubbed on the metal. When soap turns black, it means the annealing...

Explain FOUR properties of stainless steel. – NABTEB QUESTION

by Sunday | Oct 2 | NABTEB QUESTIONS

i. Corrosion resistant: Stainless steel is corrosion resistant. It is very useful where corrosion will cause damages to products. E.g. cutleries, cooking utensils. ii. Heat treatment: Martensitic stainless steel is heat treatable. This makes it useful in the...

List the uses of each of the tools used in gas welding. – NABTEB QUESTION

by Sunday | Oct 2 | NABTEB QUESTIONS

i. Colored goggle: It is used to protect the eyes from radiation of heat and sparks. ii. Spark lighter: It is used to light the blow pipe when fuel gas is released. iii. Wire brush: It is used to clean the metal surface before and after welding. iv. Hammer: It is used...