Grade: 25 Material: Chrome Steel (AISI 52100) Diameter: 5/32" Inches (3.97 millimeters) Weight: 0.00906 ounces (0.25693 grams) PGN’s G25 5/32" Chrome Steel Balls extremely precise and smooth surface guarantees you won't find any defects, such as flats, pits, soft spots, and cuts.