The Rockwell hardness scale was invented by Stanley Rockwell in 1919 to quickly assess the hardness of metal materials.
(1) HRA
① Test method and principle: ·HRA hardness test uses a diamond cone indenter to press into the material surface under a load of 60 kg, and determines the hardness value of the material by measuring the indentation depth. ② Applicable material types: ·Mainly suitable for very hard materials such as cemented carbide, ceramics and hard steel, as well as the measurement of the hardness of thin plate materials and coatings. ③ Common application scenarios: ·Manufacturing and inspection of tools and molds. ·Hardness testing of cutting tools. ·Quality control of coating hardness and thin plate materials. ④ Features and advantages: ·Fast measurement: HRA hardness test can get results in a short time and is suitable for rapid detection on the production line. ·High precision: Due to the use of diamond indenters, the test results have high repeatability and accuracy. ·Versatility: Able to test materials of various shapes and sizes, including thin plates and coatings. ⑤ Notes or limitations: ·Sample preparation: The sample surface needs to be flat and clean to ensure the accuracy of the measurement results. ·Material restrictions: Not suitable for very soft materials because the indenter may over-press the sample, resulting in inaccurate measurement results. Equipment maintenance: Test equipment needs to be calibrated and maintained regularly to ensure measurement accuracy and stability.
(2)HRB
① Test method and principle: ·HRB hardness test uses a 1/16-inch steel ball indenter to press into the material surface under a load of 100 kg, and the hardness value of the material is determined by measuring the indentation depth. ② Applicable material types: ·Applicable to materials with medium hardness, such as copper alloys, aluminum alloys and mild steel, as well as some soft metals and non-metallic materials. ③ Common application scenarios: ·Quality control of metal sheets and pipes. ·Hardness testing of non-ferrous metals and alloys. ·Material testing in the construction and automotive industries. ④ Features and advantages: ·Wide range of application: Applicable to various metal materials with medium hardness, especially mild steel and non-ferrous metals. ·Simple test: The test process is relatively simple and quick, suitable for rapid testing on the production line. ·Stable results: Due to the use of a steel ball indenter, the test results have good stability and repeatability. ⑤ Notes or limitations: ·Sample preparation: The sample surface needs to be smooth and flat to ensure the accuracy of the measurement results. ·Hardness range limitation: Not applicable to very hard or very soft materials, because the indenter may not be able to accurately measure the hardness of these materials. · Equipment maintenance: The test equipment needs to be calibrated and maintained regularly to ensure the accuracy and reliability of the measurement.
(3)HRC
① Test method and principle: · The HRC hardness test uses a diamond cone indenter to press into the material surface under a load of 150 kg, and the hardness value of the material is determined by measuring the indentation depth. ② Applicable material types: · Mainly suitable for harder materials, such as hardened steel, cemented carbide, tool steel and other high-hardness metal materials. ③ Common application scenarios: · Manufacturing and quality control of cutting tools and molds. · Hardness testing of hardened steel. · Inspection of gears, bearings and other high-hardness mechanical parts. ④ Features and advantages: · High precision: The HRC hardness test has high precision and repeatability, and is suitable for hardness testing with strict requirements. · Fast measurement: The test results can be obtained in a short time, which is suitable for rapid inspection on the production line. · Wide application: Applicable to the testing of a variety of high-hardness materials, especially heat-treated steel and tool steel. ⑤ Notes or limitations: · Sample preparation: The sample surface needs to be flat and clean to ensure the accuracy of the measurement results. Material limitations: Not suitable for very soft materials, as the diamond cone may over-press into the sample, resulting in inaccurate measurement results. Equipment maintenance: The test equipment requires regular calibration and maintenance to ensure the accuracy and stability of the measurement.
(4) HRD
① Test method and principle: ·HRD hardness test uses a diamond cone indenter to press into the material surface under a load of 100 kg, and the hardness value of the material is determined by measuring the indentation depth. ② Applicable material types: ·Mainly suitable for materials with higher hardness but below the HRC range, such as some steels and harder alloys. ③ Common application scenarios: ·Quality control and hardness testing of steel. ·Hardness testing of medium to high hardness alloys. ·Tool and mold testing, especially for materials with medium to high hardness range. ④ Features and advantages: ·Moderate load: The HRD scale uses a lower load (100 kg) and is suitable for materials with medium to high hardness range. ·High repeatability: The diamond cone indenter provides stable and highly repeatable test results. ·Flexible application: Applicable to hardness testing of a variety of materials, especially those between the HRA and HRC range. ⑤ Notes or limitations: ·Sample preparation: The sample surface needs to be flat and clean to ensure the accuracy of the measurement results. Material limitations: For extremely hard or soft materials, HRD may not be the most appropriate choice. Equipment maintenance: Test equipment requires regular calibration and maintenance to ensure measurement accuracy and reliability.
Post time: Nov-08-2024
