We present a reverse engineering method for constructing a surface approximation scheme whose input is a set of unorganized noisy points in space and whose output is a set of quadric patches. The local surface properties, necessary for the subsequent segmentation, are estimated directly from the data using a simple and efficient data structure - the neighborhood graph. Our segmentation scheme, based on principal curvatures, constructs initial point sub-sets, which may be enlarged or further subdivided based on associated approximation error estimates obtained through approximation of the initial segments by quadric surfaces. Our method is highly efficient and produces a high-quality piecewise quadric surface approximation of engineering objects, which we demonstrate for several simple and complex example data sets.