1. Material impact: Rollers, cast iron, alloy steel, etc. The density of different materials is different. The density of steel is larger than that of cast iron. Alloy steel varies according to the density and content of main alloy elements.

2. The influence of rolling and forging methods on the rolling and forging rollers is that the structure of rollers is compact, so the density is high. The structure of cast rollers, cast iron balls or cast alloy balls is not very compact, even there are air holes in them, so the density is smaller.

3. The influence of the metallographic structure of rollers: the density of martensite, austenite, bainite, ferrite and other crystalline structures are different, and the crystalline fineness is also affected.