1. Metric unit of atmospheric pressure equal to 14.50 pounds per square inch (lb/in2), 1.02 kilograms per square centimeter (kg/cm2), 29.53 inches of mercury (in Hg), or 0.9869 atmosphere. In engineering, the term 'bar gauge' (barG) is used to indicate that the pressure is read from a pressure gauge (which actually measures the difference between the fluid's pressure and the atmospheric pressure).
2. Long, solid-metal form, generally having a cross section of about 100 square centimeters. Steel bars come in two forms: (1) Merchant bars include rounds, flats, angles, squares and channels, and (2) Reinforcing bars (rebar) are used in strengthening concrete in large structures.