The firm said the problem with Skippy Reduced Fat Creamy Peanut Butter Spread was discovered on an in-line magnet check during routine cleaning.
The recall affects 16.3 ounce jars with a "Best If Used By" date of DEC1416LR1 and package UPC code of 37600-10500.
It was sent to distribution centers for Publix, Target and Walmart in Georgia, Virginia, Alabama, North Carolina, South Carolina, Delaware and Arkansas.
There have been no reports of consumer injuries or complaints and no other Skippy brand peanut butter or peanut spreads are affected.
If consumers have this product, they should return it to the store where purchased for an exchange, said the firm.