In this paper a program was build by (C#2008) programming language to calculate a dimensional change in specimens of low carbon steel during solid carburizing process. The chemical composition, mechanical properties and microstructure for all specimens was the same. Carburizing process was done in different temperatures ( 850 , 900 and
950 ) oC for holding times of ( 3 , 6 and 8 hours ) respectively flowed by normalizing , quenching and tempering to improve mechanical and microstructure properties. The specimens was measured dimensionally with high accuracy before and after mentioned above heat treatments processes to identify the change in dimensions due to change in
phases of the surface layer of metals during martenstic transformation. Briefly this work is useful in determining the right dimensions of parts before applying heat treatments to obtain the final desired dimension of the final product.