37) The gauge which is adjusted to the maximum and minimum limits is

38) The lead in a double start thread is

39) Saw tooth thread is a form of

40) A hole is to be reamed on Mild Steel with a 8mm reamer. If the u ndersize is 0.2mm and oversize is 0.05mm, diameter of the drill for drilling the hole before reaming, ideally should be

41) Predominant alloying element in stainless steel is