Electronic and atomic structure of hexagonal boron nitride (h-BN) on lattice-mismatched transition metal surfaces has been studied systematically by X-ray absorption and photoelectron spectroscopy and diffraction. The strength of interfacial chemical interaction between h-BN and the substrates is rising in the row Pt(1 1 1)-Ir(1 1 1)-Rh(1 1 1)-Ru(0 0 0 1). This rise directly correlates with a growing corrugation of the h-BN monolayer. In particular, the h-BN nanomesh has larger pores on Ru(0 0 0 1) than on the less reactive Rh(1 1 1) substrate. Our experiments provide strong evidence for the single-layer model of the nanomesh structure.