A steel I beam typically has the following important features or dimensions. (Please refer to the picture below):

## I-Beam Terminology

**Flange thickness:**Top and bottom horizontal plate-like sections of an I-beam are called flangen. The thickness of the flanges is called the flange thickness.**Flange width:**The width of the flanges is called flange width.**Beam depth:**The height between the top and bottom surface of the steel I beam is called beam depth.**Web thickness:**The vertical section of steel I beam is called web, and the thickness of the web is called web thickness.**Fillet radius:**The curved portion, where the transition between the web and flange happens is called a fillet. The radius of the fillet is called the fillet radius.

## Steps for Selecting a Correctly Sized I Beam

The overall procedure of selecting the correct size of the I beam is based upon basic mechanical design calculations as follows:

- The first input you need is the steel I beam load specifications or loading details on the steel I beam.

- Draw bending moment diagram for the given loads and you will find the value of maximum bending moments (say
**M**) that the steel I beam is expected to experience.

- Choose an approximate size of steel I beam from a standard I beam table.

- Find out the area moment of inertia (say
**I)**of the selected steel I beam.

- Get the beam depth (
**say d)**of the selected steel I beam.

- Now use the following formulae for calculating stress developed (
**f)**in the beam:

**f/(d/2)=M/ I**

**f **is the bending stress

** M** – the moment at the neutral axis

** y** – the perpendicular distance to the neutral axis

** I** – the area moment of inertia about the neutral axis

*x*

- Compare the calculated value of the bending stress with the yield stress of the steel in order to check the safety factor of your design.

## Conclusion

Correctly sized I beam selection is the first step toward correct structural design. The procedure explained above is based upon static I beam load specifications. In the cases where dynamic loads are involved, you need to use FEA tools like ANSYS, Pro Mechanica, etc.

## See also

**Five Casting Design Tips – Useful for Casting Product Designer:**Casting component design requires special attention for the successful manufacturing of a component. This article will talk about some important casting components design considerations.

**How to design a valve spring:**The valve springs are a critical component for any engine’s performance. This article will talk about how to design a valve spring.