Grade: 25 Material: Chrome Steel (AISI 52100) Diameter: 7/32" Inches (5.55625 millimeters) Weight: 0.0248 ounces (0.70503 grams) PGN’s G25 7/32" Inch Chrome Steel Balls extremely precise and smooth surface guarantees you won't find any defects, such as flats, pits, soft spots, and cuts.