Best example for gravity feed lubrication is

21) The hammer which is used for bending stretching, hammering into shoulders in side curve is called

22) On single cut files the teeth are cut parallel to other across the file at an angle of about

23) In hacksaw blade in which of the following type setting, one teeth is bent on one side, the next is kept flat and the third on the opposite side of the first

24) A thin tube is to be cut by hacksawing blades with following T.P.I which blade is appropriate for the job?