The reasons like different rock materials in various places, other sand-making line configurations, different sand-making machines, different feed particle sizes and feed volumes will all lead to differences in the gradation of machine-made sand, which will cause sand easily to use but sometimes not. Generally, the content below 0.15 is controlled not to exceed 20%, and the one below 0.08 does not exceed 10%. Therefore, machine-made sand of 2.3-2.5 is acceptable, and 2.6 is also acceptable if the gradation is good.