Due to the importance of scanning tunneling microscopy for atomic scale research the anomalously high corrugation values on close packed metal surfaces have been the subject of debate and extensive theoretical work in the past two decades. To date it remained unclear, how surface properties and electronic structures are related to forces and interactions. Here we show that elasticity, in particular the high elasticity of aluminum surfaces, enhances corrugation by up to one order of magnitude. The parameter-free simulations yield correct results for all close packed metal surfaces and emphasize the importance of atomic relaxations for chemisorption processes. (C) 2004 Elsevier B.V. All rights reserved.