Magnetized Parts

Q: Some of the steel parts that we plate are slightly magnetized. What effects if any will magnetism have on the finished product? N. S.

A: The most obvious problem that one can have when plating parts that are magnetic is that the parts will attract magnetic particles from the plating bath. This will cause a rough deposit. Obviously, this is not desirable so the parts should be demagnetized prior to plating.

In a Plating Clinic column written by Larry Durney in 1994, two cases are mentioned in which cadmium plating on steel parts was affected by magnetism. In one case steel propeller parts would not properly plate until they were put through a demagnetizing step. In a second case, bolts that had been magnetically inspected were not demagnetized prior to plating. It was found that the thread areas would not plate properly. After demagnetizing the parts plated properly.