AbstractFor the epitaxial growth of bcc(110) metals on bcc(110) metal substrates, there is a general tendency for roughening by formation of quasi-periodic ridges along [001], with up-and-down staircases in the [110] direction. It can be detected by high angular resolution Spot Profile Analysis (SPA)-LEED, as has been done previously by Hahn et al. for the case of W(110) on W(110). We found this kinetic facetting for Fe(110) on Fe(110), where it can be described by the model of layer restricted diffusion (LRD) epitaxy. We observed the same phenomenon for Fe(110) on W(110), Fe(110) on Cr(110), Cr(110) on W(110) and Cr(110) on Fe(110). In this paper, we present data for Fe(110) on Cr(110). The change between sharp single spots for in-phase energies to double spots for out-of-phase energies documents the staircase facet structure; it can be used to measure a vertical strain in the films.