1) In SI system of limits & fits, where the different types of fits are obtained by varying the size of shaft, the name given to the system is

2) The grain size of a grinding wheel is indicated by number. Which range of grain size is referred to as 'Very Fine'?

3) Unit of specific gravity is

4) Some of the interior included angles in a regular hexagon is

5) Due to continuous use, the grinding wheel of an off hand grinder is glazed locally. What tool will you use to rectify these defects?