Industries in different countries use Steel grades to classify various steel by their composition and physical properties and have been developed by a number of standard organizations.
In Basic grade designations for category 1 steels (Steel grade designation system) we use :
single letter - for designating application
number - for designating mechanical property (yield strength)
Application symbol: E
Full form: Engineering Steel
Mechanical property: Minimum Yield Strength
E is the application symbol for Engineering steel & the next set of 3 digits gives the steel's minimum yield strength.
So, E250 is an Engineering Steel standard / grade that has a minimum yield strength of 250 MPa. Further, It has the following grades: A,B (BR & BO), C that give the % of carbon i.e. 0.42 max, 0.41 max and 0.39 max respectively. The carbon percentage goes down from A to C grade i.e. if carbon percentage reduces the strength increases and weldability increases.
IS (Indian Standard)- product standard of Bureau of Indian Standards. It specifies standards for Hot-Rolled Medium and High Tensile Structural Steel & they are then issued by Bureau Of Indian standards to companies.
IS:2062- is a hot rolled structural steel that comes in three grades.
