The wire ferrule is then placed on the stripped conductor. It is important to make sure that the strands extend just outside of the ferrule barrel (approx 0.5mm). Using an approved wire ferrule crimper, select the proper cavity and crimp. Wire ferrules are sized in millimeter2 (mms), a European wire size designation of the cross sectional area. For example, a 1.5mms ferrule would use the 1.5 mms die cavity. There is not a 1:1 correspondence between mms and AWG, just an approximation.