Wood Density

Species surface hardness

 When working with various typese of woods, there is always the consideration whether we can substitute a less expensive wood for the species we are using and still get the same performance. When looking at a potential substitute, cost, availabil­ity, color and wood density can certainly be important factors.

 The importance of wood density

Wood density is very important because this property is related closely to wood strength, stiffness and nail, screw and staple holding power. We can often offset low density effects. If the strength of the wood is low, we can perhaps make the piece of lumber a little larger. If the fastener holding power is low, we can increase the fastener size or number of fasteners to achieve the required performance.

 One additional variable that is hard to compensate for by changing the design or manufacturing process is wood surface hardness. A low wood hardness, or softer woods, means that the sur­face is easy to dent; a dent can dam­age the wood fibers and give a brittle finishing coating. Crushed fibers can often be restored by steaming the damaged area briefly, finish repair is much more difficult. Softer woods, although they machine easier, are also harder to sand to a smooth finish and are more prone to have a fuzz.

 Comparing wood hardness

Surface hardness in the wood industry is measured by the load or force required to embed a steel ball, 0.444 inch in diameter, to a depth of one-half its diameter. The hardness of end grain is different from the two surfaces. I have tabulated the surface hardness for various lumber species and arranged the list from softest to hardest, even within the groups. This arrangement is similar to a ranking of lightest to heaviest.

  • Tip: If you are making cuts in hardwoods, using cermet tipped saw blades may help lengthen the life of your saw blade. 

 The data, the average of both tangential and radial surfaces (flatsawn and quartersawn), but not end grain, are from the U.S. Forest Products Lab inMadison,WI.

I have divided the list into two parts: hardwoods and softwoods. The hardwoods, which are not necessarily hard, are trees with leaves while the softwood trees have needles.

Special note: Soft maple, a lumber trade name, includes both red and silver maple. Note the difference in hardness between the two species that make this grouping. Also note the large differences between the pine, spruce and oak species. ^

 Wood Hardness

Here are two different lists for wood hardness by species.  Both are “accurtate” and both were done according to scientific principles.  However there are sub-species within species.  Wood density or hardness also varies by location grown.  Typically wood grown in a warmer climate with a longer growing season will be softer.  Wood grown in a cooler climate with a shorter growing season will be harder.  Condition of the soil and rainfall also influence the condition of the wood.  Many tropical woods, for example, are described as being “full of sand” because of the high mineral content.  

 

Hardwoods (Leaf Trees)

Very Soft (Under 450 Pounds)

Aspen

Basswood

Eastern Cottonwood

 

Quite Soft (450 To 600)

Butternut

Yellow-Poplar (Tulip Poplar)

Red Alder

Spanish Cedar

 

Moderately Soft (600 To 750)

Soft Silver Maple

 

Moderately Hard (750 To 900)

American Sycamore

True (Honduras) Mahogany

Tupelo

African Mahogany

Bigleaf (Oregon) Maple

Sweetgum

Slippery Elm

Hackberry

 

Quite Hard (900 To 1050)

Paper Birch

Cherry

Soft (Red) Maple

Teak

Black Walnut

Southern Locust

 

Very Hard (1050 To 1400)

Southern Red Oak

OregonAsh

Green Ash

Yellow Birch

Apitong & Keruing

Black Oak

Northern Red Oak

American Beech

White Ash

Rock Elm

White Oak

Bur Oak

 

Exceptionally Hard (Over 1400)

Hard Maple

Cherry-Bark Oak

Sapele

HoneyLocust

Swamp White Oak

Black Locust

Hickory

Pecan

 

Softwoods (needle trees)

Very Soft (Under 450 Pounds)

Northern White Cedar

Western Red Cedar

Atlantic White Cedar

Subalpine Fir

Eastern White Pine

Sugar Pine

Engelmann Spruce

Balsam Fir

Noble Fir

Western White Pine

Young Growth Redwood

Pacific Silver Fir

 

Quite Soft (450 To 600)

Ponderosa Pine

Old-Growth Redwood

White Fir

Lodge-Pole Pine

White Spruce

Red Spruce

Grand Fir

Eastern Hemlock

Bald Cypress

SitkaSpruce

Black Spruce

Western Hemlock

Red Pine

Jack Pine

AlaskaYellow Cedar

Tamarack

 

Moderately Soft (600 To 750)

Douglas-Fir, Interior

Spruce Pine

Loblolly Pine

Shortleaf Pine

Douglas-Fir, Coastal

Virginia Pine

 

Moderately Hard (Over 750 )

Western Larch

Longleaf Pine

 

 

Janka Scale Of Hardness for Wood Species

 

100   Balsa

350   Western Red Cedar

410   Basswood

420   White Pine

660   Douglas Fir

690   So. Yellow Pine (Loblolly & Short Leaf)

800   Honduran Mahogany

870   So. Yellow Pine (Longleaf)

950   Black Cherry

950   North American Cherry

1000 Teak

1010 Black Walnut

1010 North American Walnut

1100 Alpine Ash

1100 Heritage Oak

1100 Makore

1155 True Teak

1225 Heart Pine

1260 Red Oak

1260 Yellow Birch

1290 Angelique Teak

1290 Red Oak (Northern)

1300 American Beech

1320 White Ash

1350 Tasmanian Oak

1360 White Oak

1375 AustralianCypress

1400CaribbeanWalnut

1450 Hard Maple

1450 North American Maple

1500 Brazilian Maple

1510 Sapele

1630 Wenge

1686RoseRiverGum

1700 Locust

1710 Kempas

1720 African Blackwood

1725 African Padauk

1780 PauFerro

1820 Hickory

1820 Pecan

1820 Pecan

1860 Purpleheart

1910 Jarrah

1925 Merbau

1980 Bubinga

2023 Karri

2023 SydneyBlue

2046 Australian Beech

2135 Brushbox

2160 Goncalo Alves

2170 Asian Rosewood

2200 Bocote

2200 SantosMahogany

2300 CaribbeanRosewood

2345 Mesquite

2473 Spotted Gum

2820 Brazilian Cherry (Jatoba)

2900 Bloodwood

3000 Brazilian Rosewood (Tamarindo)

3190 Bolivian Cherry (Cerezo)

3220 Ebony

3540 Brazilian Teak (Cumaru)

3680 Brazilian Walnut (Ipe)

3800 Snakewood

4500 Lignum Vitae (Guaiacum Species Only)

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