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.

Species Janka Hardness (pounds-force)
Australian Buloke 5060[1]
Lignum vitae / Guayacan / Pockenholz 4500
Patagonian Rosewood / Curupay / Angico Preto / Piptadenia Macrocarpa / Brazilian Tiger Mahogany 3840
Snakewood / Letterhout / Piratinera Guinensis 3800
Brazilian Olivewood 3700
Brazilian Ebony 3692
Ipê / "Brazilian Walnut" / Lapacho 3684
African Pearlwood / Moabi Sometimes: Brazilian Cherry "Lite" 3680
Grey Ironbark 3664
Bolivian Cherry 3650
Lapacho 3640
Cumaru / "Brazilian Teak" sometimes: "Brazilian Chestnut," "Tiete Chestnut," "South American Chestnut," "Southern Chestnut" 3540
Ebony 3220
Brazilian Redwood / Paraju / Massaranduba 3190
Yvyraro 3040
Stranded/woven bamboo 3000
Bloodwood 2900
Red Mahogany, Turpentine 2697
"Southern Chestnut" 2670
Spotted Gum 2473
Brazilian Cherry / Jatoba 2350
Mesquite 2345
"Golden Teak" 2330
Santos Mahogany, Bocote, Cabreuva, Honduran Rosewood 2200
Pradoo 2170
Brazilian Koa 2160
Sucupira sometimes "Brazilian Chestnut" or "Tiete Chestnut" 2140
Brushbox 2135
Osage Orange[2] 2040
Karri 2030
Sydney Blue Gum 2023
Bubinga 1980
Cameron[disambiguation needed] 1940
Tallowwood 1933
Merbau 1925
Amendoim 1912
Jarrah 1910
Purpleheart 1860
Goncalo Alves / Tigerwood 1850
Hickory / Pecan, Satinwood 1820
Afzelia / Doussie / Australian Wormy Chestnut 1810
Bangkirai 1798
Rosewood 1780
African Padauk 1725
Blackwood 1720
Merbau 1712
Kempas 1710
Black Locust 1700
Highland Beech 1686
Wenge, Red Pine, Hornbeam 1630
Tualang 1624
Zebrawood 1575
True Pine, Timborana 1570
Peroba 1557
Sapele / Sapelli, Kupa'y 1510
Curupixa 1490
Sweet Birch 1470
Hard Maple / Sugar Maple 1450
Caribbean Walnut 1390
Coffee Bean 1390
Natural Bamboo (represents one species) 1380
Australian Cypress 1375
White Oak 1360
Tasmanian Oak 1350
Ribbon Gum 1349
Ash (White) 1320
American Beech 1300
Red Oak (Northern) 1290
Caribbean Heart Pine 1280
Yellow Birch, Iroko 1260
Movingui 1230
Heart Pine 1225
"Brazilian Mesquite" / Carapa Guianensis 1220
Larch 1200
Carbonized Bamboo (represents one species) 1180
Teak 1155
Cocobolo 1136
Brazilian Eucalyptus / Rose Gum 1125
Makore 1100
Siberian Larch 1100
Peruvian Walnut 1080
Boreal 1023
Black Walnut/North American Walnut 1010
Cherry 995
Black Cherry, Imbuia 950
Red Maple 950[3]
Boire 940
Paper Birch 910
Eastern Red Cedar 900
Southern Yellow Pine (Longleaf) 870
Lacewood, Leopardwood 840
African Mahogany 830
Mahogany, Honduran Mahogany 800
Parana 780
Sycamore 770
Shedua 710
Silver Maple 700[4]
Southern Yellow Pine (Loblolly and Shortleaf) 690
Douglas Fir 660
Western Juniper 626
Alder (Red) 590
Larch 590
Chestnut 540
Hemlock 500
Western White Pine 420
Basswood 410
Eastern White Pine 380
Balsa 100
Cuipo 22[1]

References[edit]

  1. ^ a b 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. ^ http://www.customworkshop.biz/wood_charts.html
  3. ^ "Red Maple". The Wood Database. 
  4. ^ "Silver Maple". The Wood Database. 

External links[edit]