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Vickers Hardness; Diamond Pyramid Hardness 
Symbol:  HV 

The Vickers Hardness test can be applied to different materials across a very wide range of hardnesses. The Vickers test uses a square-based diamond pyramid with a 136º point angle. The load (usually 50 kgf, but could be 5, 10, 20, 30, or 120 kgf) is applied via the pyramid against the smooth, firmly-supported, flat surface of the test specimen for 30 seconds. The resulting hardness reading depends on the load and the area of the permanent pyramid impression, in accordance with the formula:

Convert   HV       
(suggested range: 20 ~ 1800)
  HV   910   approximately*
Hardness
Symbol Amount Name Suggested
Range
HB (3000)  >> Brinell 10 mm Standard 3000 kgf  80~445
HB (500)  >> Brinell 10 mm Standard 500 kgf  89~189
HB (Tungsten 3000)  >> Brinell 10 mm Tungsten 3000 kgf  80~620
HB (Indentation)  2.50 mm   Brinell Indentation  6~2
HK  900   Knoop  97~920
HM  6.5   Mohs  1~10
HRA  85   Rockwell A-Scale  59~86
HRB  >> Rockwell B-Scale  41~100
HRC  67   Rockwell C-Scale  19~69
HRD  76   Rockwell D-Scale  39~77
HRF  >> Rockwell F-Scale  88~100
HR-15N  93   Rockwell Superficial 15N  69~94
HR-15T  >> Rockwell Superficial 15T  77~93
HR-30N  84   Rockwell Superficial 30N  41~85
HR-30T  >> Rockwell Superficial 30T  53~82
HR-45N  75   Rockwell Superficial 45N  19~76
HR-45T  >> Rockwell Superficial 45T  28~71
HS  95   Shore Scleroscope  17~97
Approx. TS  >> Tensile Strength (Approx.)  390~2450

Legend
<< The hardness value is below the acceptable range of the particular hardness scale.
>> The hardness value is above the acceptable range of the particular hardness scale.
### The hardness value is near the limit (within 15%) of the acceptable range of the particular hardness scale.
* The many hardness tests listed here measure hardness under different experimental conditions (e.g. indenters made in different sizes, shapes, and materials, and applied with different loads) and reduce their data using different formulae. As a result, there is NO direct analytic conversion between hardness measures. Instead, one must correlate test results across the multiple hardness tests.

This calculator is based on hardness data compiled from ASM Metals Reference Book 3rd ed, published by ASM International, and Machinery's Handbook 25th ed, published by Industrial Press. The calculator curve-fits multiple hardness data onto a common polynomial basis and then performs an analytic conversion. The accuracy of the conversion depends on the accuracy of the provided data and the resulting curve-fits, and on the valid ranges spanned by the different hardness tests. Converted hardness values should be used for comparative purposes only.

Glossary
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