This paper is intended to demonstrate the use of normalized radial basis function (NRBF) network and Bat Algorithm (BA) for size optimization of a mechanical part under static loading. The data needed for developing the NRBF model is generated simulating a parameterized CAD model in ANSYS Workbench 14.5. Plausible input data for the CAD model is created using Latin Hypercube Sampling (LHS) method. A torque arm is considered to proof the concept. The comparison between the result obtained from the proposed method and the solution from ANSYS Workbench itself shows that, the NRBF-BA model is indeed effective in providing a reasonable solution for a moderately complex problem. © (2014) Trans Tech Publications, Switzerland.