grade I standard hardness block 一级标准硬度块

grade II standard hardness block 二级标准硬度块

Vickers hardness Standard Block 标准维氏硬度块

standard block of hardness 标准硬度块

Standard micro-hardness block 标准显微硬度块

standard hardness test block [材] 标准硬度试块

Leeb Hardness standard block 里氏硬度块

Rockwell hardness standard block surface 标准表面洛氏硬度块

standard comparison hardness block 标准比对硬度块