A method of measuring plastic strain adjacent to the bar deformations has been devised, and an empirical relationship between the bar diameter, the bend former diameter and localized plastic strain determined. This has been used with a relationship between prestrain and Charpy transition temperature to determine safe bend radii for different bar diameters. A considerable advantage in the use of titanium stabilized non-strain aging grades 275 (Ti) and 415 (Ti) over the existing reinforcing bar grades 275 and 380 has also been shown.