This is an attempt to compare and contrast the various woods sold as CEDAR in North America.
The funny thing is that none of them are actually Cedar but rather are Cypress
The information on this table is for comparison purpose only. The characteristics of samples vary a great deal. These figures are from several different sources. There is a list after the table.
|Cedar type||Other Names||Location||1Modulus of Rupture||2Stiffness or Modulus of elasticity||3Janka Hardness||4Dry Weight|
|Western/Pacific redcedar, giant or western arborvitae, giant cedar, canoe cedar, shinglewood||Pacific Northwest Canada/US||7,500 lbf/in2 (51.7 MPa)||1,040,000 lbf/in2 (9.65 GPa)||390 lbf (1,734 N)||23 lbs/ft3 (368 kg/m3)|
|Yellow, Chamaecyparis nootkatensis also Cupressus nootkatensis||Alaskan yellow cedar, Nootka cypress, yellow cypress, Alaska cypress, Nootka cedar, Alaska cedar||Northwest coast of North America, Canada/US||11,100 lbf/in2 (76.6 MPa)||1,700,000 lbf/in2 (11.7 GPa)||690 lbf (3069 N)||33 lbs/ft3 (529 kg/m3)|
|Eastern Red Juniperus virginiana||Red cedar, eastern red cedar, virginian juniper, eastern juniper, Virginia Cedar, red juniper, pencil cedar, aromatic cedar.||Eastern North America, Canada/US||8,800 lbf/in2 (60.7 MPa)||880,000 lbf/in2 (6.07 GPa)||900 lbf (4,000 N)||33 lbs/ft3 (530 kg/m3)|
|Northern White Thuja occidentalis||eastern arborvidae, white cedar, swamp cedar, eastern cedar, american arborvitae, arborvitae||Northeastern North America, Canada/US||6,500 lbf/in2 (44.8 MPa)||810,000 lbf/in2 (5.58 GPa)||320 lbf (1,420 N)||22 lbs/ft3 (350 kg/m3)|
|Atlantic White Chamaecyparis thyoides||atlantic white cypress, southern white cedar, whitecedar, false-cypress||Eastern US Coastal plains.||6,800 lbf/in2 (46.9 MPa)||930,000 lbf/in2 (6.41 GPa)||350 lbf (1,560 N)||24 lbs/ft3 (380 kg/m3)|
|Port Orford Chamaecyparis lawsoniana||Lawson Cypress, pacific white cypress||Pacific northwest US, Oregon||12,290 lbf/in2 (84.8 MPa)||1,646,000 lbf/in2 (11.35 GPa)||590 lbf (2,620 N)||29 lbs/ft3 (465 kg/m3)|
|Incense Calocedrus decurrens||California incense cedar, California White Cedar,||Western North America (mostly California)||8,000 lbf/in2 (55.2 MPa)||1,040,000 lbf/in2 (7.17 GPa)||470 lbf (2,090 N)||24 lbs/ft3 (385 kg/m3)|
The reported values are not standardized and vary depending on who is reporting. For example the values for the Western Red cedar and Yellow cedar are shown higher in State of Alaska figures than in the Wood Database.com. Engineering Data Real cedar.com. Wood Structural Design Data. Engineer's Edge has material data tables. Is there an advantage in reporting high in order to encourage sales? Or is Alaska timber superior to others? A bit of both maybe. At any rate, these figures are for rough comparison only.
Most of my figures come from Gov. and Engineering sources. They usually are similar and if there is a discrepancy I use an average. Don't rely on these figures for engineering purposes or for research. They are not primary sources. I have not done these tests.
Explanation of the tests and values
1- Modulus of rupture, or Bend Strength
Units: lbf/in2 = pounds of force per square inch. MPa = Mega Pascal Mega is one million, Pascal is a unit of force defined as one newton per square meter. A newton, in the metric system, is how much force is required to make a mass of one kilogram accelerate at a rate of one metre per second per second.
Flexural strength, also known as modulus of rupture, or bend strength, or transverse rupture strength is a material property, defined as the stress in a material just before it yields in a flexure test.
A standard size sample is placed with supports at both ends and a force is applied in the middle. The sample gradually bends (flexes) as the force is applied and eventually breaks. The force is measured at the point when the sample breaks.
It is not an absolute test because results can vary. Some woods, for example, might break later if the force was applied more gradually. The test is useful as a comparison between woods.
2- Modulus of elasticity (stiffness)
Units: lbf/in2 = pounds of force per square inch. GPa = Giga Pascal Giga is billion (109 or 1,000,000,000). Pascal is a unit of force defined as one newton per square meter. A newton, in the metric system, is how much force is required to make a mass of one kilogram accelerate at a rate of one metre per second squared.
Modulus of elasticity also known as Yong's Modulus measures how stiff a sample is. It is expressed as a ratio of stress over strain. In other words, how much something bends (strain) under a given load (the stress). The higher the number, the stiffer the material.
Don't worry too much about the units. They are mostly useful to compare between the different woods.
Here is my page explaining in greater detail, Yong's Modulus in relation to carbon fibre. Carbon fibre has a yong's modulus of 181 GP compared to Western red cedar which has 7.6 GP.
3- Janka Hardness
Units: lbf = pounds of force. N = Newton, A newton, in the metric system, is how much force is required to make a mass of one kilogram go faster at a rate of one metre per second squared.
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. Commonly used to compare woods that are suitable for use as flooring.
The higher the number, the harder the wood is to dent. BALSA requires 100 pounds of force (lbf) while SUGAR MAPLE requires 1,450 lbf to embed the steel ball halfway in the sample.
4- Average Dried Weight
units: lbs/ft3 = pounds per cubic foot. kg/m3 = kilograms per Metre cubed.
In doing the measurements for the average dried weight, the moisture content is assumed to be at 12%.
Books about Wood and Woodworking
- Building cedar strip canoes
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