Removing broken screws with Alum bath
Dec 22, 2012 The alum potassium aluminum sulfate and has the chemical formula KAl SO SUB 4 /SUB SUB 2 /SUB 12H SUB 2 /SUB O readily attacks the iron component of the steel screw, particularly the threads. As a machinist we use to use this stuff to eat out broken taps out of aluminum. We would then brake it out in pieces.We had this clay that