The angle at which a board is cut determines how the finished product looks. Wood flooring is either plainsawn, quartersawn or riftsawn. 
Quartersawn flooring is a most ideal choice for installations over radiant floor heating, as recommended by the National Wood Flooring Association.

Riftsawn

Riftsawn is similar to quartersawn, but the cut is made at a slightly different angle.


The hardest wood flooring on this Janka list is not necessarily the best one to purchase. One has to make a decision based on how forgiving a wood flooring is and whether or not it will perform well in the climate you live in. 
 

Quartersawn

Quartersawing produces less board feet per log than plainsawing and is therefore is more expensive. The log is first cut into quarters and then sawn perpendicular   to the growth rings. Quartersawn wood twists and cups less, wears more evenly and is more stable. When quartersawn flooring is introduced to changing climates and humidity, the wood expands and contracts vertically instead of horizontal.

The flooring will tend to expand and contract more across the width of the boards.
 

Plainsawn

Plainsawn is the most common and least expensive method of wood flooring cuts. Plainsawn contains more variation than the other two cuts because grain patterns resulting from the growth rings are more obvious. This is the most economical method because it creates the widest boards with the least amount of waste. Plainsawn is less dimensionally stable.




The Janka (or side) hardness test measures the force required to embed a .444 inch steel ball to half its diameter in wood. This is one of the best measures of the ability of wood species to withstand denting and wear. It is also a good indicator of how hard a species is to saw or nail.

The higher the number the harder the wood

Douglas Fir
 
660
 
So. Yellow Pine (loblolly & short leaf)
 
690
 
So. Yellow Pine (longleaf)
 
870
 
Black Cherry
 
950
 
Teak
 
1000
 
Black Walnut
 
1010
 
Heart Pine
 
1225
 
Iroko - Kambala
 
1260
 
Yellow Birch
 
1260
 
Red Oak (Northern)
 
1290
 
American Beech
 
1300
 
Ash
 
1320
 
White Oak
 
1360
 
Australian Cypress
 
1375
 
Hard maple
 
1450
 
Brazilian Maple
 
1500
 
Zebrawood
 
1575
 
Wenge
 
1630
 
Kempas
 
1710
 
African Pedauk
 
1725
 
Bamboo
 
1800
 
Hickory/Pecan
 
1820
 
Purpleheart
 
1860
 
Jarrah
 
1910
 
Merbau
 
1925
 
Sydney Blue
 
2023
 
Brushbox
 
2135
 
Tigerwood
 
2160
 
Santos Mahogany
 
2200
 
Mesquite
 
2345
 
Brazilian Cherry
 
2350
 
Spotted Gum
 
2473
 
Bloodwood
 
2900
 
Tiete Rosewood
 
3200
 
Brazilian Teak
 
3540
 
Brazilian Walnut
 
3620