1. Material influence, steel, cast iron, alloy steel, etc., the density of different materials is different, the density of steel is larger than that of cast iron, and alloy steel is different according to the density and content of the main alloying elements.
2. The influence of steel ball manufacturing method, rolled and forged steel ball its structure is dense, so the density is large, the structure of cast steel ball, cast iron ball or cast alloy ball is not very dense, and even there are pores, so the density is smaller.
3. The influence of metallographic structure of steel balls, the density under different crystal structures such as martensite, austenite, bainite, ferrite is also different, and it also has an impact on the crystalline fineness.