Grade: 25 Material: Stainless Steel (AISI 440C) Diameter: 3/16 inches (4.7625 millimeter) Weight: 0.0156 ounces (0.44398 grams) PGN’s G25 3/16" Stainless Steel Bearing Balls extremely precise and smooth surface guarantees you won't find any defects, such as flats, pits, soft spots, and cuts.