Abstract: This paper compares the external expansion of a thick-walled test cylinder manufactured from EN1A free-cutting, mild steel, when subjected to an internal pressure with that of a simulated autofrettaged thick-walled cylinder cross-section, using finite element (FE) analysis. The results produced by FE are also compared with the conventional approach used for evaluating external strain in a thick-walled cylinder. This paper assumes kinematic material hardening (bilinear and multilinear) characteristics with Bauschinger effect. Comparison of results shows that those results produced by FE analysis are in good agreement with experimental results. The paper also highlights the appearance of Luder's band (stretch marks) on a thick-walled cylinder, due to plastic yielding.