Grade: 100 Material: Chrome Steel (AISI 52100) Diameter: 3-1/2", 3.5" inches (76.2 millimeter) Weight: 99.2 ounces (35.436 grams) PGN’s G100 3-1/2" Chrome Steel Balls extremely precise and smooth surface guarantees you won't find any defects, such as flats, pits, soft spots, and cuts.