The　applicability　of　constrained　groove　pressing　for　grain　refinement　and　improvements　in　mechanical　properties　of　two-phase　Cu-Zn　alloys　is　demonstrated.　It　is　shown　that　the　grain　size　and　volume　fraction　of　the　β′　phase　in　the　Cu-Zn　alloy　should　be　kept　small　through　proper　heat　treatment,　and　a　die　design　with　a　wider　groove　can　reduce　stresses　at　the　most　severely　loaded　region　of　the　workpiece,　all　of　which　allow　higher　numbers　of　pressings　to　attain　better　grain　refinement　and　improved　properties.　©　2007　Acta　Materialia　Inc.