Janka hardness test

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The Janka hardness test measures the resistance of a sample of wood to denting and wear. It measures the force required to embed an 11.28mm (.444 in) steel ball into wood to half the ball's diameter. This method leaves an indentation. A common use of Janka hardness ratings is to determine whether a species is suitable for use as flooring.

The hardness of wood varies with the direction of the wood grain. Testing on the surface of a plank, perpendicular to the grain, is said to be of "side hardness". Testing the cut surface of a stump is called a test of "end hardness".

The results are stated in various ways, which can lead to confusion, especially when the name of the actual units employed is often not attached. In the United States, the measurement is in pounds-force (lbf). In Sweden it is in kilograms-force (kgf), and in Australia, either in newtons (N) or kilonewtons (kN). Sometimes the results are treated as units, for example "660 Janka".

The Janka Hardness test results tabulated below were done in accordance with ASTM D 1037-12 testing methods. Lumber stocks tested ranges from 1" to 2" thick. The tabulated Janka Hardness numbers are an average. There is a standard deviation associated with each species, but these values are not given. It is important to note no testing was done on actual flooring. Other factors affect how flooring performs: the type of core for engineered flooring such as pine, HDF, poplar, oak, birch; grain direction and thickness; floor or top wear surface, etc. The chart is not to be considered an absolute; it is meant to help people understand which woods are harder than others.

Janka Hardness
Species (pounds-force)
Australian Buloke[1] 5060 5060
 
Schinopsis balansae, Quebracho Colorado, Red Quebracho[2] 4570 4570
 
Lignum vitae, Guayacan, Pockenholz 4500 4500
 
Piptadenia Macrocarpa, Curupay, Angico Preto, Brazilian Tiger Mahogany 3840 3840
 
Snakewood, Letterhout, Piratinera Guinensis 3800 3800
 
Brazilian Olivewood 3700 3700
 
Brazilian Ebony 3692 3692
 
Ipê, Brazilian Walnut, Lapacho 3684 3684
 
African Pearwood, Moabi 3680 3680
 
Grey Ironbark 3664 3664
 
Bolivian Cherry 3650 3650
 
Lapacho 3640 3640
 
Cumaru, Brazilian Teak 3540 3540
 
Ebony 3220 3220
 
Massaranduba, Brazilian Redwood, Paraju 3190 3190
 
Yvyraro 3040 3040
 
Bloodwood 2900 2900
 
Red Mahogany, Turpentine 2697 2697
 
Southern Chestnut 2670 2670
 
Spotted Gum 2473 2473
 
Brazilian Cherry, Jatoba 2350 2350
 
Mesquite 2345 2345
 
Golden Teak 2330 2330
 
Guatambú, Kyrandy, Balfourodendron riedelianum 2240 2240
 
Santos Mahogany, Bocote, Cabreuva, Honduran Rosewood 2200 2200
 
Pradoo 2170 2170
 
Brazilian Koa 2160 2160
 
Sucupira, Brazilian Chestnut, Tiete Chestnut 2140 2140
 
Brushbox 2135 2135
 
Osage Orange[3] 2040 2040
 
Karri 2030 2030
 
Sydney Blue Gum 2023 2023
 
Bubinga 1980 1980
 
Cameron 1940 1940
 
Tallowwood 1933 1933
 
Merbau 1925 1925
 
Amendoim 1912 1912
 
Jarrah 1910 1910
 
Purpleheart 1860 1860
 
Goncalo Alves, Tigerwood 1850 1850
 
Hickory, Pecan, Satinwood 1820 1820
 
Afzelia, Doussie, Australian Wormy Chestnut 1810 1810
 
Bangkirai 1798 1798
 
Rosewood 1780 1780
 
African Padauk 1725 1725
 
Blackwood 1720 1720
 
Merbau 1712 1712
 
Kempas 1710 1710
 
Black Locust 1700 1700
 
Highland Beech 1686 1686
 
Wenge, Red Pine, Hornbeam 1630 1630
 
Tualang 1624 1624
 
Zebrawood 1575 1575
 
True Pine, Timborana 1570 1570
 
Peroba 1557 1557
 
Sapele, Sapelli, Kupa'y 1510 1510
 
Curupixa 1490 1490
 
Sweet Birch 1470 1470
 
Hard Maple, Sugar Maple 1450 1450
 
Caribbean Walnut 1390 1390
 
Kentucky coffeetree 1390 1390
 
Natural Bamboo (represents one species) 1380 1380
 
Australian Cypress 1375 1375
 
White Oak 1360 1360
 
Tasmanian Oak 1350 1350
 
Ribbon Gum 1349 1349
 
Ash (White) 1320 1320
 
American Beech 1300 1300
 
Red Oak (Northern) 1290 1290
 
Caribbean Heart Pine 1280 1280
 
Yellow Birch, Iroko 1260 1260
 
Movingui 1230 1230
 
Heart Pine 1225 1225
 
Carapa Guianensis, Brazilian Mesquite 1220 1220
 
Larch 1200 1200
 
Carbonized Bamboo (represents one species) 1180 1180
 
Teak 1155 1155
 
Cocobolo 1136 1136
 
Brazilian Eucalyptus, Rose Gum 1125 1125
 
Makore 1100 1100
 
Siberian Larch 1100 1100
 
Peruvian Walnut 1080 1080
 
Boreal 1023 1023
 
Black Walnut, North American Walnut 1010 1010
 
Cherry 995 995
 
Black Cherry, Imbuia 950 950
 
Red Maple[4] 950 950
 
Boire 940 940
 
Paper Birch 910 910
 
Eastern Red Cedar 900 900
 
Southern Yellow Pine (Longleaf) 870 870
 
Lacewood, Leopardwood 840 840
 
African Mahogany 830 830
 
Mahogany, Honduran Mahogany 800 800
 
Parana 780 780
 
Sycamore 770 770
 
Shedua 710 710
 
Silver Maple[5] 700 700
 
Southern Yellow Pine (Loblolly and Shortleaf) 690 690
 
Douglas Fir 660 660
 
Western Juniper 626 626
 
Alder (Red) 590 590
 
Larch 590 590
 
Chestnut 540 540
 
Hemlock 500 500
 
Western White Pine 420 420
 
Basswood 410 410
 
Eastern White Pine 380 380
 
Balsa 100 100
 
Cuipo 22 22
 

References[edit]

  1. ^ Johnny W. Morlan. "Wood Species Janka Hardness Scale/Chart By Common/Trade Name A - J". The World's Top 125 Known Softest/Hardest Woods. Retrieved 20 December 2011. 
  2. ^ "The Wood Database". 
  3. ^ "Red Maple". The Wood Database. 
  4. ^ http://www.customworkshop.biz/wood_charts.html
  5. ^ "Silver Maple". The Wood Database. 

External links[edit]