Janka hardness test

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Janka hardness test.jpg

The Janka hardness test measures the resistance of a sample of wood to denting and wear. It measures the force required to embed an 11.28 mm (.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".[citation needed]

The results are stated in various ways, which can lead to confusion, especially when the actual units employed are often not attached. Overall, the resulting measure is always one of force; in SI dimensions this is ML/T2 (see SI base unit, table). 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".[1]

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.[citation needed] 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 Force: Pounds-Force (Newtons)
Australian Buloke[2] 5,060 lbf (22,500 N) 5060
 
Schinopsis brasiliensis, Quebracho, Barauna, Chamacoco[3] 4,800 lbf (21,000 N) 4800
 
Schinopsis balansae, Quebracho Colorado, Red Quebracho[4] 4,570 lbf (20,300 N) 4570
 
Lignum vitae, Guayacan, Pockenholz 4,500 lbf (20,000 N) 4500
 
Piptadenia Macrocarpa, Curupay, Angico Preto, Brazilian Tiger Mahogany 3,840 lbf (17,100 N) 3840
 
Snakewood, Letterhout, Piratinera Guinensis 3,800 lbf (17,000 N) 3800
 
Brazilian Olivewood 3,700 lbf (16,000 N) 3700
 
Brazilian Ebony 3,692 lbf (16,420 N) 3692
 
Ipê, Brazilian Walnut, Lapacho 3,684 lbf (16,390 N) 3684
 
African Pearwood, Moabi 3,680 lbf (16,400 N) 3680
 
Grey Ironbark 3,664 lbf (16,300 N) 3664
 
Bolivian Cherry 3,650 lbf (16,200 N) 3650
 
Lapacho 3,640 lbf (16,200 N) 3640
 
Cumaru, Brazilian Teak 3,540 lbf (15,700 N) 3540
 
Sucupira, Brazilian Chestnut, Tiete Chestnut 3,417 lbf (15,200 N) 3417
 
Ebony 3,220 lbf (14,300 N) 3220
 
Massaranduba, Brazilian Redwood, Paraju 3,190 lbf (14,200 N) 3190
 
Yvyraro 3,040 lbf (13,500 N) 3040
 
Strand Woven Bamboo 3,000 lbf (13,000 N) 3000
 
Cocobolo 2,960 lbf (13,200 N) 2960
 
Bloodwood 2,900 lbf (13,000 N) 2900
 
Red Mahogany, Turpentine 2,697 lbf (12,000 N) 2697
 
Live Oak 2,680 lbf (11,900 N) 2680
 
Southern Chestnut 2,670 lbf (11,900 N) 2670
 
Spotted Gum 2,473 lbf (11,000 N) 2473
 
Brazilian Cherry, Jatoba 2,350 lbf (10,500 N) 2350
 
Mesquite 2,345 lbf (10,430 N) 2345
 
Golden Teak 2,330 lbf (10,400 N) 2330
 
Guatambú, Kyrandy, Balfourodendron riedelianum 2,240 lbf (10,000 N) 2240
 
Santos Mahogany, Bocote, Cabreuva, Honduran Rosewood 2,200 lbf (9,800 N) 2200
 
Pradoo 2,170 lbf (9,700 N) 2170
 
Brazilian Koa 2,160 lbf (9,600 N) 2160
 
Brushbox 2,135 lbf (9,500 N) 2135
 
Osage Orange[5] 2,040 lbf (9,100 N) 2040
 
Karri 2,030 lbf (9,000 N) 2030
 
Sydney Blue Gum 2,023 lbf (9,000 N) 2023
 
Bubinga 1,980 lbf (8,800 N) 1980
 
Cameron 1,940 lbf (8,600 N) 1940
 
Tallowwood 1,933 lbf (8,600 N) 1933
 
Merbau 1,925 lbf (8,560 N) 1925
 
Amendoim 1,912 lbf (8,500 N) 1912
 
Jarrah 1,910 lbf (8,500 N) 1910
 
Purpleheart 1,860 lbf (8,300 N) 1860
 
Goncalo Alves, Tigerwood 1,850 lbf (8,200 N) 1850
 
Hickory, Pecan, Satinwood 1,820 lbf (8,100 N) 1820
 
Afzelia, Doussie, Australian Wormy Chestnut 1,810 lbf (8,100 N) 1810
 
Bangkirai 1,798 lbf (8,000 N) 1798
 
Rosewood 1,780 lbf (7,900 N) 1780
 
African Padauk 1,725 lbf (7,670 N) 1725
 
Blackwood[disambiguation needed] 1,720 lbf (7,700 N) 1720
 
Merbau 1,712 lbf (7,620 N) 1712
 
Kempas 1,710 lbf (7,600 N) 1710
 
Black Locust 1,700 lbf (7,600 N) 1700
 
Highland Beech 1,686 lbf (7,500 N) 1686
 
Wenge, Red Pine, Hornbeam 1,630 lbf (7,300 N) 1630
 
Tualang 1,624 lbf (7,220 N) 1624
 
Zebrawood 1,575 lbf (7,010 N) 1575
 
True Pine, Timborana 1,570 lbf (7,000 N) 1570
 
Peroba 1,557 lbf (6,930 N) 1557
 
Sapele, Sapelli, Kupa'y 1,510 lbf (6,700 N) 1510
 
Curupixa 1,490 lbf (6,600 N) 1490
 
Sweet Birch 1,470 lbf (6,500 N) 1470
 
Hard maple, Sugar Maple 1,450 lbf (6,400 N) 1450
 
Caribbean Walnut 1,390 lbf (6,200 N) 1390
 
Kentucky coffeetree 1,390 lbf (6,200 N) 1390
 
Natural Bamboo (represents one species) 1,380 lbf (6,100 N) 1380
 
Australian Cypress 1,375 lbf (6,120 N) 1375
 
White Oak 1,360 lbf (6,000 N) 1360
 
Tasmanian oak 1,350 lbf (6,000 N) 1350
 
Ribbon Gum 1,349 lbf (6,000 N) 1349
 
Ash (White) 1,320 lbf (5,900 N) 1320
 
American Beech 1,300 lbf (5,800 N) 1300
 
Red Oak (Northern) 1,290 lbf (5,700 N) 1290
 
Caribbean Heart Pine 1,280 lbf (5,700 N) 1280
 
Yellow Birch, Iroko 1,260 lbf (5,600 N) 1260
 
Movingui 1,230 lbf (5,500 N) 1230
 
Heart pine 1,225 lbf (5,450 N) 1225
 
Carapa guianensis, Brazilian Mesquite 1,220 lbf (5,400 N) 1220
 
Larch 1,200 lbf (5,300 N) 1200
 
Carbonized Bamboo (represents one species) 1,180 lbf (5,200 N) 1180
 
Teak 1,155 lbf (5,140 N) 1155
 
Brazilian Eucalyptus, Rose Gum 1,125 lbf (5,000 N) 1125
 
English Oak [6] 1,120 lbf (5,000 N) 1120
 
Makore 1,100 lbf (4,900 N) 1100
 
Siberian Larch 1,100 lbf (4,900 N) 1100
 
Peruvian Walnut 1,080 lbf (4,800 N) 1080
 
Boreal 1,023 lbf (4,550 N) 1023
 
Black Walnut, North American Walnut 1,010 lbf (4,500 N) 1010
 
Cherry 995 lbf (4,430 N) 995
 
Black Cherry, Imbuia 950 lbf (4,200 N) 950
 
Red Maple[7] 950 lbf (4,200 N) 950
 
Boire 940 lbf (4,200 N) 940
 
Paper Birch 910 lbf (4,000 N) 910
 
Eastern Red Cedar 900 lbf (4,000 N) 900
 
Southern Yellow Pine (Longleaf) 870 lbf (3,900 N) 870
 
Lacewood, Leopardwood 840 lbf (3,700 N) 840
 
African Mahogany 830 lbf (3,700 N) 830
 
Mahogany, Honduran Mahogany 800 lbf (3,600 N) 800
 
Parana 780 lbf (3,500 N) 780
 
Sycamore 770 lbf (3,400 N) 770
 
Box Elder 720 lbf (3,200 N) 720
 
Shedua 710 lbf (3,200 N) 710
 
Radiata Pine[8] 710 lbf (3,200 N) 710
 
Silver Maple[9] 700 lbf (3,100 N) 700
 
Southern Yellow Pine (Loblolly and Shortleaf) 690 lbf (3,100 N) 690
 
Douglas Fir 660 lbf (2,900 N) 660
 
Western Juniper 626 lbf (2,780 N) 626
 
Alder (Red) 590 lbf (2,600 N) 590
 
Larch 590 lbf (2,600 N) 590
 
Chestnut 540 lbf (2,400 N) 540
 
Hemlock 500 lbf (2,200 N) 500
 
Western White Pine 420 lbf (1,900 N) 420
 
Basswood 410 lbf (1,800 N) 410
 
Eastern White Pine 380 lbf (1,700 N) 380
 
Balsa 100 lbf (440 N) 100
 
Cuipo 22 lbf (98 N) 22
 

References[edit]

  1. ^ Pedersen, Jason. "The Janka Hardness Test". Low Cost Flooring. Retrieved 18 March 2016. 
  2. ^ 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. 
  3. ^ "GlobalSpecies.org". 
  4. ^ "The Wood Database". 
  5. ^ "Red Maple". The Wood Database. 
  6. ^ "English Oak". The Wood Database. Retrieved 28 August 2015. 
  7. ^ http://www.customworkshop.biz/wood_charts.html
  8. ^ "Radiata Pine". The Wood Database. 
  9. ^ "Silver Maple". The Wood Database. 

External links[edit]