Kalmar "Allen screw" tana nufin nau'in dunƙule wanda ke da soket ɗin hexagonal (wanda ake kira Allen key ko Allen wrench) a kai. An ƙera wannan soket ɗin don a juya shi tare da maɓallin Allen ko maƙarƙashiya don ƙara ko sassauta dunƙule. Ana amfani da sukurori na Allen sau da yawa a cikin injina, lantarki, da sauran aikace-aikace inda ake buƙatar ƙaramin bayanin martaba da ƙarfin juzu'i mai ƙarfi. Sunan "Allen screw" ya fito ne daga alamar kasuwanci na ainihin masana'anta, Kamfanin Manufacturing Allen.