Modeling for forward extrusion with square dies of a variety of Al alloys was conducted with DEFORM(TM) finite element (FEM) software. The constitutive data were largely generated by torsion testing over 300-500degreesC and 0.1-5 s(-1). In addition to load stroke curves for various extrusion ratios, billet temperatures and ram speeds, the distributions within the billet were determined for temperature, strain, strain rate and mean stress; these permitted estimation of surface cracking and product microstucture from the torsion results. From the load-stroke analysis, it seems that alloys with considerable solute such as 5000 series (similar to5% Mg) and 7000 series have limitations on extrudability from the pressure requirements. On the other hand an alloy such as 2618 has constraints on billet temperature and rate due to possible incipient melting at the surface. Comparison is made to alloy composites bearing particles or fibers of Al2O3 or SiC; these do exhibit increased load compared to the respective alloy. The 6061 composites still have better extrudability than some 5000 and 7000 alloys.