Hardness is the most important property of die steel, considering toughness and other properties, the best range of die hardness is a relatively narrow interval. Because its hardness requirements in a very narrow range, so the test instrument accuracy requirements will be very high, in a long time, the hardness test of finished products, semi-finished products die is a difficult problem to solve. Originally, only a few small volume and weight of the mold can be moved to the bench Rockwell hardness tester to test, for the large volume and weight of the mold has no choice but to use the Richter hardness tester instead. Now the portable Rockwell hardness tester has perfectly solved the hardness testing problem in the die industry. The portable Rockwell hardness tester PHR-100 is small in size and weighs only 4.7kg. It can be moved freely by a single person. The hardness test can be completed by contacting the parts on one side during the test, without moving the parts. The test operation is fast, convenient and will not cause damage to the test mold. The instrument has convenient reading, good repeatability and high test accuracy. Among them, PHR-100 portable Rockwell hardness tester has been widely used by die factories, and it has indeed made up for the defects of Leed hardness tester in practical application, and brought more accurate hardness testing tools for die industry