... -1, American Standard ASTM E18, ASTM E110.PHR Series Portable Superficial Rockwell Hardness Tester has produced two specifications. Model PHR ... and Φ1.588mm two pressure head, with 15kg, 30kg, 45kg power of three tests, test HR15T, HR30T, HR45T, HR15N, HR30N, ... and the blade's hardness. Technical parameter:ModelHZ-2507B PHR Portable rockwell hardness testerHardness scaleRockwell—A , B , C , D , E , ...