The use of the Rockwell hardness tester HR-150A mainly consists of three steps: preparation, testing, and reading. The key is to select the appropriate scale and indenter, and the operation should be smooth. ‌‌

How do I operate it specifically?

Preparation: Place the hardness tester flat, clean the oil stains on the sample surface, select the appropriate indenter, and calibrate the equipment.

Apply load: Place the test sample, rotate the handwheel to allow the indenter to lightly touch the surface until the small pointer points to the red dot and the large pointer rotates three times.

Reading record: Pull the loading handle to apply the main load, maintain it for about 10 seconds, then remove the load, and directly read the value from the dial. ‌‌

How to choose a scale indenter?

HRC scale: used for measuring hard materials such as quenched steel and tempered steel, with a diamond indenter, and reading the black numbers on the dial.

HRB scale: used for measuring softer materials such as mild steel and non-ferrous metals, with a steel ball indenter, and reading the red numerals on the dial.

HRA scale: used for measuring hard alloys or thin hard steel strips, also employs a diamond indenter, suitable for extremely hard materials. ‌‌

What are the precautions to take?

Sample requirements: The surface should be flat and smooth, and the thickness should generally not be less than 3mm. Too thin a sample may lead to inaccurate measurements.

Test spacing: Measure different points on the same sample, ensuring that the distance between the indentation centers is at least 3 millimeters, and avoid the edges.

Equipment maintenance: After use, cover the dust cover properly. Regularly check the wear of the pressure head. Before long-term disuse, it needs to be recalibrated.