Economet RH- 150 Manual Rockwell Hardness Tester by mechanical project manual testing, no electronic device Rockwell hardness affordable plan has good economic and practical, wide range, simple operation, etc. Usage Range:Hardened steel, the tempering steel, steel, steel rolling, annealing cold malleable iron, aluminum alloy, and copper and so on, Usage Range:Hardened steel, the tempering steel, steel, steel rolling, annealing cold malleable iron, aluminum alloy, and copper and so on.