Hardness Conversion Calculator
Table of contents
Different hardness scalesSteel hardness conversion chartCalculating hardness conversion with this calculatorFAQsOur hardness conversion calculator enables you to convert steel hardness from one scale to another. You're not the first to wish for an accurate conversion from Brinell hardness number to Rockwell or Vickers scale and vice versa. But for the reasons we'll get to in the following article, this conversion is only approximate!
Below, we shall briefly look at the three different hardness scales before learning how to convert HB to HRC or calculate HV to HRB with the help of a hardness conversion chart.
Different hardness scales
The hardness number of a material indicates its resistance to plastic deformation. The higher the hardness number, the higher the hardness of the material. We get these numbers by performing indentation tests on the material. The three standard hardness scales in use are:
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Brinell hardness number (HB, HBW, or BHN), which depends on the diameter of the spherical indentor and the indentation. You can learn more about this with our Brinell hardness number calculator.
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Rockwell hardness number, calculated from the indentation depth. Different scales under the Rockwell scale are labeled HRA, HRB, HRC, etc. For more on the Rockwell hardness, visit our Rockwell hardness conversion calculator.
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Vickers hardness number (HV), independent of the indentor size, is one of the broadest hardness scales used. Our Vickers hardness number calculator will help you calculate the HV of any material.
Steel hardness conversion chart
The hardness of steel depends on several factors, such as its composition, manufacturing, and heat-treating processes. The different hardness scales use different loads, different indentor shapes, and different measurements to obtain the hardness number. There are no straightforward formulae to establish relationships between the different scales, making accurate conversion impossible in most cases.
However, the following steel hardness conversion table was tabulated through extensive data, allowing for approximate conversions.
Brinell HB | Rockwell C HRC | Rockwell B HRB | Vickers HV |
|---|---|---|---|
800 | 72 | -- | -- |
780 | 71 | -- | -- |
760 | 70 | -- | -- |
752 | 69 | -- | -- |
746 | 67 | -- | -- |
745 | 68 | -- | -- |
735 | 66 | -- | -- |
711 | 65 | -- | -- |
695 | 64 | -- | -- |
681 | 63 | -- | -- |
658 | 62 | -- | -- |
642 | 61 | -- | -- |
627 | 60 | -- | -- |
613 | 59 | -- | -- |
601 | 58 | -- | 746 |
592 | 57 | -- | 727 |
572 | 56 | -- | 694 |
552 | 55 | -- | 649 |
534 | 54 | 120 | 589 |
513 | 53 | 119 | 567 |
504 | 52 | 118 | 549 |
486 | 51 | 118 | 531 |
469 | 50 | 117 | 505 |
468 | 49 | 117 | 497 |
456 | 48 | 116 | 490 |
445 | 47 | 115 | 474 |
430 | 46 | 115 | 458 |
419 | 45 | 114 | 448 |
415 | 44 | 114 | 438 |
402 | 43 | 114 | 424 |
388 | 42 | 113 | 406 |
375 | 41 | 112 | 393 |
373 | 40 | 111 | 388 |
360 | 39 | 111 | 376 |
348 | 38 | 110 | 361 |
341 | 37 | 109 | 351 |
331 | 36 | 109 | 342 |
322 | 35 | 108 | 332 |
314 | 34 | 108 | 320 |
308 | 33 | 107 | 311 |
300 | 32 | 107 | 303 |
290 | 31 | 106 | 292 |
277 | 30 | 105 | 285 |
271 | 29 | 104 | 277 |
264 | 28 | 103 | 271 |
262 | 27 | 103 | 262 |
255 | 26 | 102 | 258 |
250 | 25 | 101 | 255 |
245 | 24 | 100 | 252 |
240 | 23 | 100 | 247 |
233 | 22 | 99 | 241 |
229 | 21 | 98 | 235 |
223 | 20 | 97 | 227 |
216 | 19 | 96 | 222 |
212 | 18 | 95 | 218 |
208 | 17 | 95 | 210 |
203 | 16 | 94 | 201 |
199 | 15 | 93 | 199 |
191 | 14 | 92 | 197 |
190 | 13 | 92 | 186 |
186 | 12 | 91 | 184 |
183 | 11 | 90 | 183 |
180 | 10 | 89 | 180 |
175 | 9 | 88 | 178 |
170 | 7 | 87 | 175 |
167 | 6 | 86 | 172 |
166 | 5 | 86 | 168 |
163 | 4 | 85 | 162 |
160 | 3 | 84 | 160 |
156 | 2 | 83 | 158 |
154 | 1 | 82 | 152 |
149 | -- | 81 | 149 |
147 | -- | 80 | 147 |
143 | -- | 79 | 146 |
141 | -- | 78 | 144 |
139 | -- | 77 | 142 |
137 | -- | 76 | 140 |
135 | -- | 75 | 137 |
131 | -- | 74 | 134 |
127 | -- | 72 | 129 |
121 | -- | 70 | 127 |
116 | -- | 68 | 124 |
114 | -- | 67 | 121 |
111 | -- | 66 | 118 |
107 | -- | 64 | 115 |
105 | -- | 62 | 112 |
103 | -- | 61 | 108 |
95 | -- | 56 | 104 |
90 | -- | 52 | 95 |
81 | -- | 41 | 85 |
76 | -- | 37 | 80 |
For example, let's consider a conversion from HV to HRC. Say the steel sample's hardness is 262 HV. By looking up 262 HV on this table, you can see its Rockwell C equivalent is 27 HRC.
You can skip such manual steps by instead asking our calculator to convert HV to HRC. The following section teaches you how best to use this calculator.
🔎 What if, instead of 262 HV, you need to convert 269 HV to HRC?
Generally, when the hardness number you need to convert falls between two values in the table, we reach for the lower value instead of the upper one. Since 269 HV falls between 262 HV and 271 HV on the table, we go for 262 HV and use that to convert to other scales.
Calculating hardness conversion with this calculator
Our calculator can convert steel hardness between different scales in two steps:
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Select which hardness number you want to convert from. You can choose from the following:
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Brinell hardness number;
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Rockwell C scale;
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Rockwell B scale; and
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Vickers hardness number.
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Enter the hardness number. The calculator will convert it to all the other remaining hardness scales!
What is the Vickers hardness number of steel with 300 BHN?
The equivalent hardness of a steel sample of 300 BHN in the Vickers scale is 303 HV. To perform this conversion, refer to a steel harness conversion chart and follow these steps:
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Look up the Brinell hardness,
300 BHN. -
Find the equivalent Vickers hardness in the same row,
303 HV. -
Verify your result with our hardness conversion calculator.
What is the hardness of mild steel?
Mild steel has an approximate Rockwell hardness number of 70 HRB, equivalent to 121 BHN (Brinell hardness number) and 127 HV (Vickers).
What is the relationship between hardness and tensile strength of steel?
In steel, indentation hardness varies linearly with its tensile strength. However, this relationship is "imperfect" – limited to small ranges of hardness and tensile strength.
What are the units of Brinell, Rockwell, and Vickers hardness numbers?
Brinell and Vickers hardness numbers use the unit kgf/mm2, similar to pressure. On the other hand, Rockwell hardness (scales B and C) are dimensionless quantities.