In Weyger's "The Complete Modern Blacksmith" he talks of re-purposing worn out picks into smaller one-hand picks. What he would do is take a heat focused on one side of the eye, quenching the opposite side of the eye if necessary to keep it from changing shape. Then he would beat down the hot side, causing the steel to upset (get thicker and shorter). The cold side of the eye would keep its shape, forcing the upset. Then he'd do the other side the same way. The result was a smaller shorter eye with thicker walls.