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 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, e.g., "660 Janka".
Wood Flooring Species / Janka Hardness (pounds-force)
- Lignum vitae 4500
- Brazilian Ebony 3692
- Ipê / "Brazilian Walnut" / Lapacho 3684
- African Pearlwood / Moabi 3680
- Bolivian Cherry 3650
- Lapacho 3640
- "Brazilian Teak" 3540
- Ebony 3220
- Brazilian Redwood / Paraju 3190
- Yvyraro 3040
- 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 2200
- Pradoo 2170
- Brazilian Koa 2160
- Sucupira sometimes "Brazilian Chestnut," "Tiete Chestnut," "Brazilian Walnut" 2140
- 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
- Black 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
- 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 Kambala 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
- Peruvian Walnut 1080
- Boreal 1023
- Black Walnut/North American 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
- African Mahogany 830
- Mahogany, Honduran Mahogany 800
- Parana 780
- Sycamore 770
- Shedua 710
- Southern Yellow Pine (Loblolly and Shortleaf) 690
- Douglas Fir 660
- Alder (Red) 590
- Larch 590
- Chestnut 540
- Hemlock 500
- White Pine 420
- Basswood 410
- Eastern White Pine 380
- Balsa 100
