DATA SOURCE(S): 12,16,36,55,56
Common Name(s): Holm oak, encina, evergreen oak, holly oak, azinho
Scientific Name: Quercus ilex
Distribution: Native to Mediterranean region; also naturalized in the United Kingdom
Tree Size: 65–85 ft (20–25 m) tall,
3–4 ft (1–1.2 m) trunk diameter
Average Dried Weight:AVERAGE DRIED WEIGHT
Density is the measurement of a wood’s weight per unit volume. Here, "dried weight" specifically refers to wood at 12% moisture content, and values are given in pounds per cubic foot and kilograms per cubic meter. Also keep in mind that density commonly varies by +/- 10% from the average.
Click on the link "Average Dried Weight" for more details. 60.0 lbs/ft3 (960 kg/m3) High WEIGHT TIERS
Extremely Low: 0+ kg/m3
Very Low: 420+ kg/m3
Low: 520+ kg/m3
Medium-Low: 620+ kg/m3
Medium: 730+ kg/m3
Medium-High: 840+ kg/m3
High: 960+ kg/m3
Very High: 1,080+ kg/m3
Extremely High: 1,200+ kg/m3
Tiers are based on CSIRO provisional strength groupings (SD1-SD8) based on density.
Janka Hardness:JANKA HARDNESS
This test measures a wood’s resistance to indentation, and is the pounds of force (or Newtons) required to embed a .444" (11.28 mm) diameter steel ball halfway into the wood. Values are for side grain, measured at 12% MC.
Click on the link "Janka Hardness" for more details. 2,590 lbf (11,520 N)* High JANKA HARDNESS TIERS
Extremely Low: 0+ N
Very Low: 2,050+ N
Low: 3,150+ N
Medium-Low: 4,480+ N
Medium: 6,280+ N
Medium-High: 8,380+ N
High: 11,080+ N
Very High: 14,000+ N
Extremely High: 17,450+ N
Tiers are derived from CSIRO provisional strength classifications (SD1-SD8) in conjunction with the USDA's estimated hardness based on density.
*Estimated hardness based on specific gravity.
Modulus of Rupture:MODULUS OF RUPTURE
Sometimes called bending strength, this test measures a wood’s strength before breaking (i.e., rupturing). Values are given in pounds of force per square inch and megapascals, measured at 12% MC.
Click on the link "Modulus of Rupture" for more details. 21,220 lbf/in2 (146.4 MPa) Very High MOR TIERS
Extremely Low: 0+ MPa
Very Low: 45+ MPa
Low: 55+ MPa
Medium-Low: 65+ MPa
Medium: 78+ MPa
Medium-High: 94+ MPa
High: 110+ MPa
Very High: 130+ MPa
Extremely High: 150+ MPa
Tiers are based on CSIRO strength classifications (SD1-SD8).
Elastic Modulus:MODULUS OF ELASTICITY
This test measures the wood’s level of deformation when under a given load. Higher values indicate less deformation (i.e., stiffer). Values are given in pounds of force per square inch and gigapascals, measured at 12% MC.
Click on the link "Elastic Modulus" for more details. 1,945,000 lbf/in2 (13.41 GPa) Medium MOE TIERS
Extremely Low: 0+ GPa
Very Low: 7.9+ GPa
Low: 9.1+ GPa
Medium-Low: 10.5+ GPa
Medium: 12.5+ GPa
Medium-High: 14.0+ GPa
High: 16.0+ GPa
Very High: 18.5+ GPa
Extremely High: 21.5+ GPa
Tiers are based on CSIRO strength classifications (SD1-SD8).
Crushing Strength:CRUSHING STRENGTH
Also called compression strength, this test measures the maximum stress sustained before failure. Force is applied parallel to the grain (producing stress akin to chair legs). Values are given in pounds of force per square inch and megapascals, measured at 12% MC.
Click on the link "Crushing Strength" for more details. 8,840 lbf/in2 (61.0 MPa) High CRUSHING STRENGTH TIERS
Extremely Low: 0+ MPa
Very Low: 30+ MPa
Low: 36+ MPa
Medium-Low: 41+ MPa
Medium: 47+ MPa
Medium-High: 54+ MPa
High: 61+ MPa
Very High: 70+ MPa
Extremely High: 80+ MPa
Tiers are based on CSIRO strength classifications (SD1-SD8).
Shrinkage:SHRINKAGE
These values represent the percentage change in radial and tangential faces of the wood—as well as the total (volumetric) shrinkage—as the moisture content goes from green (maximum) down to oven-dry (minimum), approximating the wood's stability with changes in humidity. T/R ratio helps to estimate the uniformity of the shrinkage across different wood faces.
Click on the link "Shrinkage" for more details. Radial: 4.5%, Tangential: 6.7% High SHRINKAGE TIERS
Very Low: 0%+
Low: 3.6%+
Medium: 5.1%+
High: 6.6%+
Very High: 8.1%+
Tiers are based on tangential shrinkage (green to oven-dry) from CSIRO shrinkage classifications (1-5).
Volumetric: 18.6%, T/R Ratio: 1.5
Color/Appearance: Medium reddish brown, generally darker in color than other common European oaks such as Quercus robur or Q. petrea. Most pieces of holm oak lack annual earlywood pore rings but have wider, more pronounced rays, leading to strong ray fleck on quarter sawn surfaces, as well as conspicuous rays appearing as darker reddish lines even on rift and flat sawn surfaces. Since Holm oak typically lacks clearly delineated growth rings, figure like cathedral grain is mostly absent and isn’t enhanced much by applying a pigment stain.
Grain/Texture: Grain tends to be irregular and interlocked. Since holm oak is commonly diffuse porous, the grain and texture tends to be more uniform than other oaks. Good natural luster.
Rot Resistance: Good rot resistance.
Workability: Generally difficult to work on account of both its density and also the irregular grain. Also, the wood dries very slowly and has a tendency to warp and check during drying. However, holm oak glues and finishes well.
Odor: Has a tell-tale smell that is common to most oaks. Most find it appealing.
Allergies/Toxicity: Although severe reactions are quite uncommon, oak has been reported as a sensitizer. Usually most common reactions simply include eye and skin irritation, as well as asthma-like symptoms. See the articles Wood Allergies and Toxicity and Wood Dust Safety for more information.
Pricing/Availability: Due to the tree’s somewhat twisted growth pattern, as well as the wood’s high density and difficulty in drying, holm oak isn’t really a commercial species of oak. It’s likely only available in very limited sizes and quantities in or around its natural range surrounding the Mediterranean Basin. It’s more common to see this wood sold locally as firewood.
Sustainability: This wood species is not listed in the CITES Appendices, and is reported by the IUCN as being a species of least concern.
Common Uses: Tool handles, knife scales, parquet flooring, turned objects, and firewood.
Comments: The term “holm” is another word for holly, so named because the foliage of Quercus ilex resembles holly. Indeed, in an unusual chicken-and-egg precedent, this oak species was classically referred to in Latin as ilex,[1]Pliny. Natural History, Volume IV: Book 6, Section 87. Translated by H. Rackham. Loeb Classical Library 370. Cambridge, MA: Harvard University Press, 1945. and when Carl Linneas first classified holly species under the Ilex genus in 1753,[2]Linnaeus, C (1753). Species Plantarum. it was derived from the leaf shape of the holly oak. (This is highly unusual, as typically it’s the broader genus classification that lends itself to naming narrower species-level characteristics. For instance, the specific epithets alnifolia or laurifolia are used across many different genera and refers to species that are alder-leaved or laurel-leaved, derived from the genera Alnus and Laurus, respectively.)
It’s these characteristic thick, waxy holly-like leaves that enable holm oak to thrive in the hotter and drier climates of the Mediterranean. Holm oak trees are non-deciduous and are sometimes known as evergreen oak. Anatomically, the wood shares a lot of similarities with species of live oak (such as Quercus suber and Q. virginiana).
Images: Drag the slider up/down to toggle between raw and finished wood.
A special thanks to Nick Taylor for providing the image of the knife scales.
Holm oak with flat sawn grain
Do you have images of projects made from this wood species? You can submit them to me here.
Identification: See the article on Hardwood Anatomy for definitions of end grain features.
Porosity:POROSITY
Specifies the overall pore structure (ring-porous, semi-ring-porous, or diffuse porous), and notes if annual growth rings may still be seen even for diffuse porous hardwoods.
Click on the link “Porosity” for more details. diffuse porous (or semi-ring porous with pore size gradually decreasing in the latewood); growth rings possibly indicated by lighter-color or flattened fibers—see notes below
Arrangement:ARRANGEMENT
Describes the more individual pore arrangements found throughout the end grain surface, such as solitary, multiples, chains, clusters, etc.
Click on the link “Arrangement” for more details. exclusively solitary, arranged radially or in dendritic pattern
Vessels:VESSELS
Describes the relative size and frequency of the pores (vessels), as well as any contents found in the pores, such as tyloses, colored mineral deposits, etc.
Click on the link “Vessels” for more details. large to very large, few; tyloses occasionally present and can even be present in sapwood (believed to be a result of distress)[3]Balzano, A., Čufar, K., & De Micco, V. (2021). Xylem and Phloem Formation Dynamics in Quercus ilex L. at a Dry Site in Southern Italy. Forests, 12(2), 188.
Rays:RAYS
Describes the relative width and frequency of the rays (appearing as thin vertical lines on the endgrain), as well as a note on if these rays are visible with/without magnification.
Click on the link “Rays” for more details. rays of two distinct sizes: narrow and very wide, normal to close spacing; large aggregate rays are easily visible without magnification
Lookalikes/Substitutes: Bears a very close resemblance to other evergreen/live oaks, especially cork oak (Quercus suber), which also shares a somewhat overlapping geographic distribution.
Notes: It’s not clear if the zones of lighter-color fibers indeed correspond to annual growth rings, or are some other cyclical pattern in the wood. James Gamble commented “growth slow, rings uncertain; if the concentric rings in No. H 1406 are annual rings the growth of that specimen was 70 rings in 4 inches of radius.”[4]Gamble, J. S. (1902). A manual of Indian timbers. (p. 674). He goes on to describe another study where trees were found to have an average number of these concentric rings numbering 20 per inch.
Related Content:
References
| ↑1 | Pliny. Natural History, Volume IV: Book 6, Section 87. Translated by H. Rackham. Loeb Classical Library 370. Cambridge, MA: Harvard University Press, 1945. |
|---|---|
| ↑2 | Linnaeus, C (1753). Species Plantarum. |
| ↑3 | Balzano, A., Čufar, K., & De Micco, V. (2021). Xylem and Phloem Formation Dynamics in Quercus ilex L. at a Dry Site in Southern Italy. Forests, 12(2), 188. |
| ↑4 | Gamble, J. S. (1902). A manual of Indian timbers. (p. 674). |
The Holm Oak end grain on the data base isnt very high res but it really looks too ring porous in vessel pattern . ?
Well spotted. I live in Greece within the natural area of distribution where Holm Oak does not show growth rings. Moreover it can have dark brown, extensive, heartwood and be a lot heavier by volume than what is stated. It takes an incredible glassy lustered polish, it’s less prone to cracking compared with Holm Oak grown in the UK. Traditionally it ‘s used [in Greece at least] for wooden mallets and for cogs in wind and water mill cogwheels. The offcuts make very good fuel.
Hi, I would really like to know if there is and way to differentiate between Holm oak and Live / Virginian Oak purely by the end grain pattern .
hhh2 is Holm oak but the unknown is hhh1, very similar vessels but the Holme tends to be a single radial line of vessels whereas hhh1 is multiple….does this mean it is not Holme? could it be Live Oak ?
in reviewing other endgrain images of holm oak on NCSU’s Inside Wood, I can see that there are instances when holm oak can be more diffuse porous like your images. Definitely within the realm of possibility that yours is still holm oak.
Thanks for looking into that . yep it might be Holm, but ‘if’ it is Virginian is there a way to prove its Virginian /Live and not Holm. is there anything other than vessel distribution that distinguishes the two apart. The photo is of a bowl I turned from driftwood found on Lyme Regis Beach . it had obviously been in the sea; on the sea bed for a long time, wonderful evidence of Teredo navalis bore holes. I am trying to prove whether this is local Holm oak or Virginian Oak from maybe driftwood Beach Gorgia curtesy of the… Read more »
Bowl
From my reading into the nature of holm oak many years ago , when got a wind blown limb from an old wood .
1. Beautiful grain colouring like the plumage of a trush
2. Seasoned well with less cracking or shakes than common oaks . Air dry for best results.
3. Use in olden times for strong load bearing parts in wooden ship building.
Hi Tomas, thank you for this very important info. I’m from the Netherlands and I’m also sure that the values from wood database are far from correct. It is indeed much harder and dense as they describe it. In the north of Europe it grows in England that I know of, but it can’t be compared to holmoaks in southern Europe for sure. I’m surprised that wood database didn’t answer your comment after more then a year or even bother to correct the values for holmoak. It’s an amazing wood. In the Netherlands it’s used in windmills for centuries. A… Read more »
i’m mot a wood technician but rather a designer-maker. i just made a box for the ashes of my mate jerry out of holm oak that we got from a local park back in 2015, hence reasonably well seasoned as it was cut into 3/4″ planks. from working with it, i can say it machines as if it were even harder than english oak, it feels even denser and the silvergrain is quite magnificent unfortunately, given its use this time, i am not going to be able to keep an eye on how well it ages but i would be… Read more »
Hi Tim, I’m a retired wood consultant, originally from the Netherlands but awhile ago when we retired we moved to Crete, Greece — Chania prefecture. There’s a lot of holm oak over here. It sure is a lot harder than any other European oak, possibly with the exception of Quercus coccifera which looks quite similar [talking about the wood]. It takes on a glassy polish, will readily sink in water no matter how well dried. Formerly [and to a limited degree, still] used for mallets, cogs in cogwheels, and other mechanical applications. The trouble is, it’s very hard. So sawmills… Read more »
Hi Harold… I live in Chania, Greece, having moved here nearly 10 years ago when we had the option of prepensioen. The local holm oak is way heavier than what is described; one — admittedly rather fresh — piece weighed in at 1.45 kilo/liter. When well dry — that takes a lot of time — the weight by volume will still be very high, estimate 1.15-1.2. The local holm oak has the reputation of not cracking; but you have to slowly air dry it.
Hi Willem, I’ve been in Crete 10 years ago and have picked up some oak wood (curved piece) which isn’t holmoak but has a similar coarse grain. It’s much lighter in weight, do you know what this is? It’s been 6 years since my first comment and I find it strange the density is still listed as 800 kg/m3. I measured a dried piece that I have and that is 952 kg/m3. Significally more dense than the description but also much lighter than the 1150-1200 kg/m3 you estimated. That seems a bit too heavy to be true imho. No holm… Read more »
hi! im really sorry to say so, but i cant help noticing the values for holm oak are not relevant to the species Quercus ilex that grows in Spain. i assume its not easy to find relevant information in english, but since this tremendously heavy and hard wood is a tree very common to Spain, it is possible to find information in Spanish. the only drawback is they do not use the Janka test, but the Monnin wood hardness test. the hardness value of Quecus Ilex is 14.3 – measured by the Madrid Polytechnical university. in Spanish Hollyoak is Encina.… Read more »
Thanks Tomas, again for great info that comes from a university who did thorough research, I feel sad you never got a reply from wood database. The density you mentioned is 967 – 1045 kg/m3, that’s even a bit more dense than the piece I have with 952 kg/m3. Comes very close to the minimum density you described though. It’s indeed extremely hard and I can’t think of a harder wood in Europe. I remember someone describe it once hard as nails.