The bolts in a rigid flanged coupling connecting two shafts transmitting power are subjected to shear Force and Bending moment.

The bolts in a rigid flanged coupling connecting two shafts transmitting power are subjected to shear Force and Bending moment.

**Atmospheric pressure**: The atmospheric air exerts a normal pressure upon all surfaces with which it is in contact and it is known as **atmospheric pressure**. Atmospheric pressure is also known as **barometric pressure**. The atmospheric pressure at sea level (above absolute zero) is called **standard atmospheric pressure** and its value is given as follows:

**Standard atmospheric pressure** = 101.3 kN/m^{2} or kPa (1 kN/m^{2} = 1 kPa)

= 10.3 m of water

= 760 mm of Hg

Atmospheric pressure = Absolute pressure - Gauge pressure

**Gauge Pressure**: The pressure measured with the help of a pressure gauge is known as **gauge pressure**, in which atmospheric pressure is taken as datum. All the pressure gauges record the difference between the actual pressure and the atmospheric pressure. The actual pressure is known as **absolute pressure**. Mathematically

Absolute pressure= Atmospheric pressure + Gauge pressure (Positive)

**Vacuum pressure**: For pressures below atmospheric, the gauge pressure will be negative. This negative gauge pressure is known as **vacuum pressure**. Therefore

Absolute pressure = Atmospheric pressure - Negative gauge pressure or vacuum pressure

H7g6 fit provided on an assembly is A clearance fit.

A Newtonian fluid is defined as one with constant viscosity, with zero shear rate at zero shear stress, that is, the shear rate is directly proportional to the shear stress.