Grain Size Measurement: This can be part of the microstructure examination or can be conducted by it self as an inspection tool after say a forging operation, a heat treat operation, a rolling operation, etc. Typically the finer the grain size the better the material condition. Most alloy steels require ASTM 5 or finer grain size and some tool steels require 8 or finer grain size.

-ASTM E 112 – Standard Test Methods for Determining Average Grain Size.-

Grain Flow Analysis: This type of analysis detects and examines the flow of the granular structure after a forming operation, a forging operation, thread forming operation, etc. This is crucial to determining the quality of say a forging operation or a welding operation such as inertia/friction welding. This examination will determine if the grain flow is continuous and resolved and follows the contour of the part. This will also determine after a welding operation (inertia/friction weld) if the weld created two relatively equally heated surfaces that have a combined grain flow. This is crucial for strength and soundness of the material. It is performed though proper preparation and hot acid etching  and examination.