... the surface of hardened steel, hardened sheet metal ROCKWELL HARDNESS TESTERModel MRR (M)-150D1 LCD digital Rockwell -Superficial Rockwell ... beautiful shape, combinating of common superficial Rockwell hardness tester and superficial Rockwell Hardness Tester , expanding the scope of use, ... , eliminats of human operation and reading errors.The hardness tester is appropriate for hard alloy, carbide, the ...