1. Asnafi N. Tool design in cold heading of fasteners: part I—literature survey and analytical modelling, Swedish Institute for Metals Research IM-3332. December 1995.
2. Asnafi N. Tool design in cold heading of fasteners: part II—finite element simulations and experimental analysis, Swedish Institute for Metals Research IM-3333. March 1996.
3. Berns H et al. A new material for cold forging tools. Computational Materials Science 1998;11:166–80.
4. Thuvander A et al. Numerical and experimental simulation of cold forging of a collar hex-bolt. Swedish Institute for Metals Research IM-2867. June 1992.
5. Private communication with Mr Christoph Broeckmann, Lehrstuhl Werkstofftechnik, Ruhr-Universität, Bochum, Germany.