When working with metals, it’s easy to confuse the hardness of different alloys. Even within one metal type, there are many variations in the exact properties. In general, metals are either softer or harder than others. However, it can be difficult to know how hard a specific metal is when comparing one type to another.
To help you understand this concept better, we have created a chart that explains how to convert Leeb to Vickers Hardness measurements.
I. What is HL in Hardness?
HL is used to represent the value of the hardness of material under the Leeb hardness testing. The HL value is calculated by getting the ratio between the carbide or tungsten ball velocity before and after it hits the test material.
II. What is HV in Hardness?
HV is a unit of measurement used for the Vickers hardness testing. It represents the value of hardness in terms of depth of penetration under the Vickers scale. It can also be calculated by multiplying the velocity of the tungsten carbide ball that strikes against the test material with its diameter. The calculation uses a standard formula, which will vary depending on the style and shape of the diamond indenters used to test the material’s hardness.
III. How do you Convert HLD to HV?
HLD (corresponds to Leeb) is the measure of hardness for materials that are softer than those that can be applied with the Vickers hardness test. The HLD value is calculated by dividing the hardness of the diamond by a Leeb hardness number. There will be a constant conversion between the two, depending on how hard the tested material is. Depending on the ASTM standards, there is also a hardness conversion table.
These conversion tables follow specific parameters such as the indenters and the force applied.
IV. Leeb to Vickers Hardness Conversion Table
Leeb (HLD; Type D Impact Device) | Vickers (HV; 1kg) |
565 | 285 |
557 | 278 |
550 | 272 |
542 | 261 |
539 | 258 |
530 | 250 |
526 | 246 |
521 | 240 |
518 | 235 |
510 | 226 |
505 | 221 |
497 | 217 |
491 | 213 |
485 | 209 |
482 | 201 |
478 | 199 |
474 | 197 |
468 | 190 |
463 | 186 |
461 | 184 |
459 | 183 |
455 | 177 |
449 | 174 |
443 | 171 |
439 | 168 |
437 | 165 |
434 | 162 |
430 | 159 |
425 | 154 |
423 | 152 |
420 | 150 |
417 | 149 |
413 | 147 |
411 | 146 |
408 | 144 |
405 | 142 |
404 | 141 |
389 | 135 |
390 | 130 |
365 | 120 |
350 | 110 |
331 | 100 |
321 | 95 |
300 | 85 |
287 | 80 |
Leeb (HLD; Type D Impact Device) | Vickers (HV; 5kg) |
856 | – |
850 | 1220 |
843 | 1210 |
837 | 1114 |
829 | 1060 |
824 | 1021 |
812 | 940 |
806 | 905 |
799 | 867 |
787 | 803 |
782 | 775 |
776 | 746 |
770 | 727 |
763 | 694 |
751 | 649 |
748 | 639 |
739 | 606 |
731 | 587 |
724 | 565 |
719 | 551 |
709 | 534 |
699 | 502 |
693 | 489 |
688 | 474 |
677 | 460 |
669 | 435 |
660 | 423 |
650 | 401 |
640 | 390 |
635 | 385 |
630 | 380 |
622 | 361 |
617 | 352 |
613 | 344 |
605 | 335 |
599 | 320 |
588 | 312 |
579 | 305 |
572 | 291 |
565 | 285 |
557 | 278 |
550 | 272 |
542 | 261 |
539 | 258 |
530 | 250 |
526 | 246 |
521 | 240 |
518 | 235 |
510 | 226 |
505 | 221 |
497 | 217 |
491 | 213 |
485 | 209 |
482 | 201 |
478 | 199 |
474 | 197 |
468 | 190 |
463 | 186 |
461 | 184 |
459 | 183 |
455 | 177 |
449 | 174 |
443 | 171 |
439 | 168 |
437 | 165 |
434 | 162 |
430 | 159 |
425 | 154 |
423 | 152 |
420 | 150 |
417 | 149 |
413 | 147 |
411 | 146 |
408 | 144 |
405 | 142 |
404 | 141 |
389 | 135 |
390 | 130 |
365 | 120 |
350 | 110 |
331 | 100 |
321 | 95 |
300 | 85 |
287 | 80 |
Leeb (HLD; Type D Impact Device) | Vickers (HV; 10 kg) |
828 | 762 |
819 | 737 |
809 | 711 |
800 | 688 |
791 | 667 |
782 | 645 |
773 | 625 |
764 | 605 |
755 | 586 |
746 | 568 |
737 | 550 |
729 | 534 |
720 | 517 |
712 | 503 |
703 | 487 |
695 | 473 |
687 | 460 |
679 | 447 |
671 | 434 |
663 | 422 |
655 | 410 |
647 | 398 |
640 | 388 |
632 | 377 |
625 | 368 |
618 | 358 |
611 | 349 |
603 | 339 |
596 | 330 |
590 | 323 |
583 | 314 |
576 | 306 |
570 | 299 |
563 | 291 |
557 | 284 |
551 | 277 |
545 | 271 |
539 | 264 |
533 | 258 |
527 | 251 |
521 | 245 |
516 | 240 |
510 | 234 |
Conclusion
Material hardness is important because it directly impacts the performance of the material used to create it. This can be either in terms of durability or resistance to wear. Also, this value plays a very important role in determining whether something can be used as a structural component or not.
As a result, it is important that you find out the exact hardness of the alloys that you are trying to identify. This can help in selecting one type over another. It is also important to know how to convert Leeb hardness to Vickers hardness under different conditions. These conditions could vary depending on the type of indenters used or the force applied.