The following two conversion tables come from standard ASTM A 370….Formula A – Convert HRC into HB.
| Rockwell C Hardness (HRC) | Brinell Hardness (HB) |
|---|---|
| From 21 to 30 | HB = 5.970 * HRC + 104.7 |
| From 31 to 40 | HB = 8.570 * HRC + 27.6 |
| From 41 to 50 | HB = 11.158 * HRC – 79.6 |
| From 51 to 60 | HB = 17.515 * HRC – 401 |
How does Brinell hardness relate to Rockwell hardness?
Brinell hardness (HB) is generally used for the soft material, such as non-ferrous metals, steel before heat treated or after annealing. Rockwell hardness (HRC) is generally used for high hardness materials, such as the hardness after heat treatment and so on.
What is the difference between Rockwell and Brinell?
The Brinell method is used for soft and medium hard materials. Rockwell’s test is used for soft and medium hard materials (aluminum, soft steel, Cu alloys etc.)
Is Brinell more accurate than Rockwell?
A Brinell hardness tester can test all types of metals. The results of the Brinell method are more accurate and reliable than those obtained by the Rockwell method because the use of a spherical indenter distributes pressure evenly.
What is the Brinell hardness number?
The Brinell hardness number is a number proportional to the load or test force of a hard steel ball to the calculated curved area of the indentation formed. The ball diameter is 1, 2.5, 5, or 10 mm.
What is the difference between Rockwell Brinell and Vicker hardness testing?
Making use of a diamond indenter, the Vickers hardness test is done with less force and more accuracy than the Brinell test. Requiring an optical system and material prep, the Vickers test incurs higher costs and takes longer to complete than the Rockwell test.
Why is Brinell better than Rockwell?
Brinell Hardness Unlike with Rockwell testing, Brinell tests measure the diameter of the indentation made by the ball, not the depth. Because the indentation ball is so much larger than in other testing methods, hardness values derived from the test provide a more representative average hardness of the part.
What is the Brinell hardness of mild steel?
130
Typical Brinell Hardness Numbers for Metals
| Material | Brinell Hardness Number |
|---|---|
| Mild steel | 130 |
| Annealed chissel steel | 235 |
| White cast iron | 415 |
| Nitrided surface | 750 |
How do you read Brinell hardness?
A Brinell hardness value consists of the following components:
- The numeric hardness value;
- The three letters “HBW”, standing for “Hardness according to Brinell” (with hard metal ball made from tungsten carbide);
- The ball diameter in mm;
- The applied test load in kgf;
What is BHN where it is used?
Most commonly it is used to test materials that have a structure that is too coarse or that have a surface that is too rough to be tested using another test method, e.g., castings and forgings.
What is the Rockwell hardness scale?
The Rockwell scale is a hardness scale based on indentation hardness of a material. The Rockwell test determines the hardness by measuring the depth of penetration of an indenter under a large load compared to the penetration made by a preload. There are different scales, denoted by a single letter, that use different loads or indenters.
What is Rockwell hardness number?
Rockwell hardness number. A measure of Rockwell hardness; determined by use of a machine having an indentor which can be loaded; the number is derived from the net increase in depth of impression that the indentor makes in the material as the load on the indentor is increased from a fixed load to a higher load, and then returned to the minimum load.
What is Brinell hardness number?
Brinell hardness number. (brɪˈnɛl) n. ( General Engineering ) a measure of the hardness of a material obtained by pressing a hard steel ball into its surface; it is expressed as the ratio of the load on the ball in kilograms to the area of the depression made by the ball in square millimetres.
What is Rockwell B C scale?
Rockwell Hardness Scales. Several different Rockwell scales are used for various materials and hardnesses. The most common are the Rockwell B and Rockwell C scales. The Rockwell B system incorporates a 1/16 th inch diameter steel ball, with a load of 100kg for softer materials such as aluminium alloys and materials of similar hardness.
