10-pc. ceramic disc magnet set. Each measures 1/2in. dia. x 3/16in. thick. Also known as ferrite magnets these powerful discs are made from the highest grade of ceramic available giving them unbeatable pull strength. They are highly resistant to demagnetization and resistant to corrosion. This magnet can be attached to any medium-weight project using most types of adhesive. Place this magnet in a tractor s oil pan to attract steel bits that collect in the oil from grinding pistons.