Janka Wood Hardness Rating 3739769 224521296 2008-07-09T06:13:06Z Ethel Aardvark 4037911 {{cleanup|date=February 2008}} {{Orphan|date=February 2008}} {{unreferenced|date=February 2008}} The '''Janka test''' measures the force required to embed a 11.28 millimeter (0.444 inch) steel ball into wood to half its diameter. This method was chosen so that the result would leave an indention 100 square millimeters in size. It is one of the best measures of the ability of a wood species to withstand denting and wear. It is also a good indicator of how hard a species is to saw or nail. The [[hardness]] of wood usually varies with the direction of the [[wood grain]]. If testing is done on the surface of a plank, perpendicular to the grain, the test is said to be of "side hardness." Testing the cut surface of a stump would be 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 [[pound-force|pounds-force]] (lbf). In Sweden it is in [[kilogram-force|kilograms-force]] (kgf), and in Australia, either in [[newton]]s (N) or kilonewtons (kN). Sometimes the results are treated as units, e.g., "660 Janka." A common use of Janka hardness ratings is to determine whether a species is suitable for use as flooring. {| class="wikitable" |- ! Wood Flooring Species ! Janka Hardness |- | Ipe / Brazilian Walnut / Lapacho | 3684 |- | Cumaru / Brazilian Teak | 3540 |- | Ebony | 3220 |- | Brazilian Redwood / Paraju | 3190 |- | Angelim Pedra | 3040 |- | Bloodwood | 2900 |- | Red Mahogany, Turpentine | 2697 |- | [[Corymbia maculata|Spotted Gum]] | 2473 |- | [[Jatoba|Brazilian Cherry / Jatoba]] | 2350 |- | Mesquite | 2345 |- | Santos Mahogany, Bocote, Cabreuva | 2200 |- | Pradoo | 2170 |- | [[Tristania conferta|Brushbox]] | 2135 |- | Karri | 2030 |- | Sydney Blue Gum | 2023 |- | Bubinga | 1980 |- | Cameron | 1940 |- | Tallowwood | 1933 |- | Merbau | 1925 |- | Amendoim | 1912 |- | Jarrah | 1910 |- | Purpleheart | 1860 |- | Goncalo Alves / Tigerwood | 1850 |- | Hickory / Pecan, Satinwood | 1820 |- | Afzelia / Doussie | 1810 |- | Bangkirai | 1798 |- | Rosewood | 1780 |- | African Padauk | 1725 |- | Blackwood | 1720 |- | Merbau | 1712 |- | Kempas | 1710 |- | Locust | 1700 |- | Highland Beech | 1686 |- | Wenge, Red Pine | 1630 |- | Tualang | 1624 |- | Zebrawood | 1575 |- | True Pine, Timborana | 1570 |- | Peroba | 1557 |- | Kambala | 1540 |- | Sapele / Sapelli | 1510 |- | Curupixa | 1490 |- | Sweet Birch | 1470 |- | Hard Maple / Sugar Maple | 1450 |- | Coffee Bean | 1390 |- | Natural Bamboo (represents one species) | 1380 |- | [[Callitris|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 | 1260 |- | Movingui | 1230 |- | Heart Pine | 1225 |- | Carbonized Bamboo (represents one species) | 1180 |- | Cocobolo | 1136 |- | Brazilian Eucalyptus / Rose Gum | 1125 |- | Makore | 1100 |- | Boreal | 1023 |- | Black Walnut | 1010 |- | Teak | 1000 |- | Sakura | 995 |- | Black Cherry, Imbuia | 950 |- | Boire | 940 |- | Paper Birch | 910 |- | Cedar | 900 |- | Southern Yellow Pine (Longleaf) | 870 |- | Lacewood, Leopardwood | 840 |- | Parana | 780 |- | Sycamore | 770 |- | Shedua | 710 |- | Southern Yellow Pine (Loblolly and Shortleaf) | 690 |- | [[Douglas Fir]] | 660 |- | Larch | 590 |- | Chestnut | 540 |- | Hemlock | 500 |- | White Pine | 420 |- | Basswood | 410 |- | Eastern White Pine | 380 |} == External links == *[http://www.countyfloors.com/about_janka.html Janka Hardness Scale For Wood Flooring Species] *[http://www.sizes.com/units/janka.htm Janka Hardness Scale For Wood - Side Hardness Chart of Some Woods] *[http://www.fpl.fs.fed.us/documnts/fplgtr/fplgtr113/fplgtr113.pdf USDA - Wood Handbook - Wood as an Engineering Material] *[http://www.fpl.fs.fed.us/documnts/fplrn/fpl_rn303.pdf USDA - Janka Hardness Using Nonstandard Specimens] [[Category:Woodworking]] [[Category:Woodcarving]] [[Category:Wood]] [[Category:Hardness tests]] {{woodworking-stub}}