Grade: 25 Material: Stainless Steel (AISI 440C) Diameter: 5/32 inches (3.96875 millimeter) Weight: 0.00906 ounces (0.25693 grams) PGN’s G25 5/32" Stainless Steel Bearing Balls extremely precise and smooth surface guarantees you won't find any defects, such as flats, pits, soft spots, and cuts.