An $$HSS$$ drill of $$20mm$$ diameter with $$5mm$$ cone height is used to drill a through hole in a steel work-piece of $$50mm$$ thickness. Cutting speed of $$10m/min$$ and feed rate of $$0.3mm/rev$$ are used. The drilling time, in seconds, neglecting the approach and over travel, is ______________

Reaming is a process used for

Match the following:

A spindle speed of $$300$$ $$rpm$$ and a feed $$0.3mm/revolution$$ are chosen for longitudinal turning operation on an engine lathe. In finishing pass, roughness on the work surface can be reduced by