Grade: 25 Material: Chrome Steel (AISI 52100) Diameter: 3/4, 0.75 inches (19.05 millimeter) Weight: 1.002 ounces (28.4152 grams) PGN’s G25 3/4" Inch Chrome Steel Balls extremely precise and smooth surface guarantees you won't find any defects, such as flats, pits, soft spots, and cuts.