以一定的載荷(一般3000kg)把一定大小(直徑一般為10mm)的淬硬鋼球壓入材料表面，保持一段時間，去載后，負荷與其壓痕面積之比值，即為布氏硬度值(HB)，單位為公斤力/mm2(N/mm2)。

2.洛氏硬度(HR)

當HB>450或者試樣過小時，不能采用布氏硬度試驗而改用洛氏硬度計量。它是用一個頂角120°的金剛石圓錐體或直徑為1.59、3.18mm的鋼球，在一定載荷下壓入被測材料表面，由壓痕的深度求出材料的硬度。根據(jù)試驗材料硬度的不同，分三種不同的標度來表示：HRA：是采用60kg載荷和金剛石壓頭押入器求得的硬度，用于硬度極高的材料(如硬質合金等)。HRB：是采用100kg載荷和直徑1.58mm淬硬的鋼球，求得的硬度，用于硬度較低的材料(如退火鋼、鑄鐵等)。HRC：是采用150kg載荷和金剛石壓頭押入器求得的硬度，用于硬度很高的材料(如淬火鋼等)。

With a certain load (generally 3000kg), the hardened steel ball of a certain size (generally 10mm in diameter) is pressed into the surface of the material and kept for a period of time. After the load is removed, the ratio of the load and the indentation area is the Brinell hardness value (HB), and the unit is kg force /mm2(N/mm2).

2. Rockwell Hardness (HR)

When HB>450 or the sample is too small, the Brinell hardness test should not be used, but rockwell hardness measurement. It is to use a diamond cone with a top Angle of 120° or a steel ball with a diameter of 1.59 or 3.18mm to press into the surface of the measured material under a certain load, and the hardness of the material can be calculated by the depth of the indentation. According to the hardness of test materials, there are three different scales: HRA: hardness obtained by 60kg load and diamond indenter, used for materials with high hardness (such as hard alloy, etc.). HRB: the hardness is obtained by using 100kg load and 1.58mm diameter hardened steel ball, used for low hardness materials (such as annealed steel, cast iron, etc.). HRC: hardness obtained by 150kg load and diamond indenter for high hardness materials (such as hardened steel, etc.).