Related KPSC ITI JTO Engineering Drawing Question Paper 2018 with Answer Key
horizontal plane
.Orthographic plane on which the top view is obtained is horizontal plane.

small fractions of unit of measurement
Diagonal scale: Plain scales cannot be used for taking smaller measurement. The distance between the consecutive divisions on a plain scale, at best can only be 0.5 mm. In other words, the smallest measurement that can be taken. Using a plain scale of RF 1:1 is 0.5 mm. If the RF of a plain scale is 1:5, the smallest measurement such a scale can take is 2.5 mm (0.5 mm x 5).

pitch
Distance of centre of one rivet to the centre of next rivet measured parallel to the seam is called pitch.

shaft diameter is smaller than hole diameter
In Clearance fit, the largest permitted shaft diameter is smaller than the diameter of the smallest hole, so that the shaft can rotate or slide through with different degrees of freedom according to the purpose of mating members.
