Wires from zone-refined crystal D were tensile tested at room temperature. These wires were tested in the as-drawn-with-lubricant condition. Tensile properties of the wire from crystal D were determined as a function of wire-drawing strain. It was found that, on the average, the zone-refined beryllium work-hardened at about the same rate as did commercially-pure beryllium. The room temperature strength level of the zonerefined material was about half that of the commercially-pure wire. Room temperature ductility in the as-drawn condition was not very purity-sensitive.