hardness number

例句：

1. 1. The material has a hardness number of 60 on the Rockwell scale.
   该材料的洛氏硬度值为60。
2. 2.The hardness number is an important factor in determining the strength of the material.
   硬度数值是决定材料强度的一个重要因素。
3. 3. To ensure the quality of the product, we need to measure the hardness number regularly.
   为了确保产品质量，我们需要定期测量硬度数值。