Topic of this work is to compare metalurgy of cast irons poured into sand moulds and into shell molds at IEG Jihlava company and from it

following differencies in structures of thin- and thick-walled castings. This work is dealing with investigation and experimental

measurement on surfaces and sections suitable thin- and thick-walled investment castings at IEG Jihlava. Cast irons with flake graphite

(grey cast iron) and cast irons with spheroidal graphite (ductile cast iron). Both mechanical and physical properties are determined using

calculations from as measured values of wall thicknesses L and Lu, Vickers hardness and remanent magnetism. Measurement results are

discussed, findings are formulated and methods for castings metallurgical quality improvement are recommended finally

Reason for and risks of using of cast iron with vermicular graphite for typical construction parts. Ultrasound checking of graphite shape. Factors influencing plausibility of result. Difference between laboratory and operation application. Roughness, parallelism, stabilityand size dimension of walls. Conditions, proposals for simplification and productivity enhancement of castings checking. Recommendation.