HEY CLONE BOY, but u talking about ARMATURE BAR for coils machines?
impossible work that is not MAGNETIC MATERIAL, the only way u have for ALUMINIM ARMATURE BAR, is put a insert of IRON inside where the HEAD of the coils touch the ARMATURE BAR, that's all

but not realy have to much sense have ALUMINIUM A.-BAR, for what? for go more fast? probable the machine like that gonna run more than 160 HZ, is to fast, no good for tattoos

U EVER BUILD MACHINES BEFORE ?