Which of the following would be considered secondary process

Which of the following would be considered secondary processes, as opposed to basic processes (four correct answers): annealing are welding drilling electroplating extrusion to produce steel automotive components impression die forging painting plastic injection molding rolling of sheet steel sand casting sheet-metal stamping sintering of pressed ceramic powders ultrasonic machining

Solution

a) arc welding

b) Plastic injection molding

c) impression die forging

d) Sinetering of pressed ceramic powders