430pcs 6 size precision steel balls assortment kit contains:50pcs1/4" 50pcs7/32" 50pcs3/16" 80pcs5/32" 100pcs1/8" 100pcs3/32". Made of 304 Stainless Steel.Uniform size, high wear resistance, high precision， smooth surface, no burr, exquisite appearance. Widely used in auto parts, motorcycles, bicycles bearings, casters, drawer slides etc. It can also be used as a mixing balls. Used to stir paint, nail polish, etc The surface is coated with a small amount of grease to reduce friction when the bearing rotates and prevent corrosion and rust.Will reduce the damage to the machine and extend the service life. Storage box packaging. steel balls are sorted by size . There are explanatory drawings. Easy to identify and store.