Check here various Brinell To Rockwell Hardness Conversion
Different Conversion of Brinell To Rockwell C Conversion, Brinell To Rockwell B Conversion and Brinell To Rockwell Chart
Seamless Pipe
Welded Pipe
ERW Pipe
Difference Between Brinell and Rockwell Hardness
- Indenters of Brinell and Rockwell Hardness
- In case of Brignell’s method, the penetrator is a calcareous ball (for hardness up to 450HB) or hard metal (for hardness up to 650HB) of diameter D, which is emitted by force F in the surface layers of the material. The standard diameters of balls are 10, 5, 2.5, 2 and 1 mm.
- In Rockwell’s method several types of penetrators are used: for soft materials, a small steel ball (HRB method) is used, for hard materials a diamond cone (HRC method). The diamond cone has a peak angle of 1200 and a radius of 0.2 mm round, while the diameter of the steel balls is 1/16″, 1/8″, 1/4″ and 1/2″.
- Duration of Brinell and Rockwell Hardness
- The Brinell test is very slow (30 – 60sec).
- Rockwell’s test is shorter (10 – 15sec).
- Calculation of Brinell and Rockwell Hardness
- Brinell’s Hardness (HB) is the ratio of the applied force F (N) and the surface of the fingerprint S (mm2): HBW = (F*0.102/ S); S = π* D* h.
- In Rockwell’s method HRB = 130 – (e/0.002); HRC = 100 – (e/0.002)
- Application of Brinell and Rockwell Hardness
- 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.)
- Advantages of Brinell and Rockwell Hardness
- Advantages of Brinell’s method is the simple surface preparation and the easy measurement of the print diameter.
- Rockwell method is faster, there is higher speed immediate reading of hardness on the device and the test leaves shallow imprint.
- Disadvantages of Brinell and Rockwell Hardness
- Disadvantages of Brinell’s method are that hardness of ≥ 650 HB cannot be measured; the hardness is dependent on the load and according to X (degree of load) so it is necessary to choose the appropriate force F; after the measurement, the impression is large and leaves a visible trace.
- For Rockwell’s test there is the possibility of a cone breakage and the imprecision ± 2 HRB / HRC.
- Rockwell Hardness Test
- Quick and cost-effective process
- The Rockwell hardness is based on difference of indentation depth of indenter from two different load applications.
- Not always the most accurate hardness testing method
- No specimen preparation required
- Ball Indenter 1/16 , 1/8 , 1/4 and 1/2 inches diameter.
- Testing Load - Two loads Minor 10Kgf, Major 60 -100-150 Kgf
- Hardness value is directly readable , no optical evaluation required
- Non-destructive testing
- First minor load is applied to achieve zero level then major load is applied for specific period.
- Indenter Size - Conical diamond indenter with 120° Included angle.
- Brinnel Hardness Test
- In Brinell hardness test hard ball indenter is pressed under load on surface of material.
- Indenter- Ball indenter e.g. 1mm, 2.5mm, 5mm and 10mm ball diameter
- High risk of deforming the materials to be tested when testing in micro range with very high test loads.
- Teating Load - Single load from 1kgf to 3000 Kgf
- Process is very slow ( the test cycle takes somewhere between 30 and 60 seconds )
- It can be applied on thin specimens of very hard materials.
- Can be used to test non-homogenous materials ( castings ).
- Surface quality of the metal must be very good because the indent is measured optically.
- Brinell hardness number is expressed as ratio of load and area of indentation.
Hardness ranges for heat treated steel
| Heat Treated Condition |
Q | R | S | T | U | V | W | X | Z |
|---|---|---|---|---|---|---|---|---|---|
| Tensile Strength |
625-775 n/mm2 |
700-850 n/mm2 |
775-925 n/mm2 |
850-1000 n/mm2 |
925-1075 n/mm2 |
1000-1150 n/mm2 |
1075-1225 n/mm2 |
1150-1300 n/mm2 |
1550 n/mm2 |
| Hardness Brinell |
179-229 | 201-225 | 223-277 | 248-302 | 269-331 | 293-352 | 311-375 | 345-401 | 444 |
HARDNESS CONVERSION TABLE
| Brinell Hardness |
Rockwell Hardness | Tensile Strength |
||
| A Scale | B Scale | C Scale | ||
| 3000KG Ball | 60KG | 100KG | 150KG | (Approx.) |
| 400 | 72.0 | – | 43.1 | 202,000 |
| 388 | 71.4 | – | 41.8 | 195,000 |
| 375 | 70.6 | – | 40.4 | 188,000 |
| 363 | 70.0 | – | 39.1 | 182,000 |
| 352 | 69.3 | 110.0 | 37.9 | 176,000 |
| 341 | 68.7 | 109.0 | 36.6 | 170,000 |
| 331 | 68.1 | 108.5 | 35.5 | 166,000 |
| 321 | 67.5 | 108.0 | 34.3 | 160,000 |
| 311 | 66.9 | 107.5 | 33.1 | 155,000 |
| 302 | 66.3 | 107.0 | 32.1 | 150,000 |
| 293 | 65.7 | 106.0 | 30.9 | 145,000 |
| 285 | 65.3 | 105.5 | 29.9 | 141,000 |
| 277 | 64.6 | 104.5 | 28.8 | 137,000 |
| 269 | 64.1 | 104.0 | 27.6 | 133,000 |
| 262 | 63.6 | 103.0 | 26.6 | 129,000 |
| 255 | 63.0 | 102.0 | 25.4 | 126,000 |
| 248 | 62.5 | 101.0 | 24.2 | 122,000 |
| 241 | 61.8 | 100.0 | 22.8 | 118,000 |
| 235 | 61.4 | 99.0 | 21.7 | 115,000 |
| 229 | 60.8 | 98.2 | 20.5 | 111,000 |
| 223 | – | 97.3 | 18.8 | 109,000 |
| 217 | – | 96.4 | 17.5 | 105,000 |
| 212 | – | 95.5 | 16.8 | 102,000 |
| 207 | – | 94.6 | 15.2 | 100,000 |
| 201 | – | 93.8 | 13.5 | 98,000 |
| 197 | – | 92.8 | 12.7 | 95,000 |
| 192 | – | 91.9 | 11.5 | 93,000 |
| 187 | – | 90.7 | 10.0 | 90,000 |
| 183 | – | 90.0 | 9.0 | 89,000 |
| 179 | – | 89.0 | 8.0 | 88,000 |
| 174 | – | 87.8 | 6.4 | 86,000 |
| 170 | – | 86.8 | 5.4 | 84,000 |
| 167 | – | 86.0 | 4.4 | 83,000 |
| 163 | – | 85.0 | 3.3 | 82,000 |
| 156 | – | 82.9 | – | 80,000 |
| 149 | – | 80.8 | – | 73,000 |
| 143 | – | 78.7 | – | 71,000 |
| 137 | – | 76.4 | – | 67,000 |
| 131 | – | 74.0 | – | 65,000 |
| 126 | – | 72.0 | – | 63,000 |
| 121 | – | 69.8 | – | 60,000 |
| 116 | – | 67.6 | – | 58,000 |
| 111 | – | 65.7 | – | 56,000 |