Modulus of Rupture, frequently abbreviated as MOR, (sometimes referred to as bending strength), is a measure of a specimen’s strength before rupture. It can be used to determine a wood species’ overall strength; unlike the modulus of elasticity, which measures the wood’s deflection, but not its ultimate strength. (That is to say, some species of wood will bow under stress, but not easily break.)

Modulus of rupture (MOR) testing

Modulus of rupture (MOR) testing

MOR is expressed in pounds-force per square inch (lbf/in2) or megapaschals (MPa). This number is given for wood that has been dried to a 12% moisture content, unless otherwise noted.


In practical terms, the number itself isn’t all that meaningful, but it becomes useful to use in comparison with other woods. For instance, Hickory is known to have excellent strength properties among domestic species in the US, and has a MOR of 20,200 lbf/in2 (139.3 MPa). In comparison, Red Oak is another well-known wood used in cabinetry and furniture, and has a MOR of 14,300 lbf/in2 (98.6 MPa).

Get the hard copy

wood-book-standupIf you’re interested in getting all that makes The Wood Database unique distilled into a single, real-world resource, there’s the book that’s based on the website—the best-seller, WOOD! Identifying and Using Hundreds of Woods Worldwide. It contains many of the most popular articles found on this website, as well as hundreds of wood profiles—laid out with the same clarity and convenience of the website—packaged in a shop-friendly hardcover book.


  1. Collins January 1, 2019 at 1:33 pm - Reply

    What is the size of the sample and specifics of the fulcrum points (Distance, length, shape) Also, I’m guessing that the MOR number is the highest force reached and not the force being applied at the time of rupture, is this correct?

  2. Ernie Smith November 25, 2018 at 2:16 pm - Reply

    First and foremost, thank you for compiling, formatting and sharing this data publicly. The data is incredibly useful.

    Second, can you point me to some additional resources that explain how the MOR tests are done for wood? I am curious how specimens are selected, what grain direction is used, size of test pieces, sample size, etc.

    Again, thank you for this wonderful resource.


    • Eric November 27, 2018 at 2:55 pm - Reply

      I don’t know all of the particulars off the top of my head, and I don’t know if that information is publicly available. ASTM would be happy to sell you that info for about $70!

  3. Christina Foley November 1, 2018 at 6:02 am - Reply

    What is the specimen size used to determine MOR presented here. I’m assuming 20 x 20 x360 mm, can you verify?

    Thank you!

  4. student that needs help October 8, 2018 at 2:51 am - Reply

    for a school project i need to develop my own furniture but i have trouble with the MOR.
    width length & depth should have impact on the amount of pascal it can withstand, but when i go to Wikipedia it says Pa = n/m^2 wich means that only depth and length have influence on the MOR
    what should i do when i need to know how thick i need to make my table for more than 4 students to sit on

    • Eric October 10, 2018 at 3:50 pm - Reply

      It’s a bit misleading to only look at the units of measurement for the strength rating. (The imperial units are even more straightforward, rated in pounds per SQUARE inch.) However, these tests are performed on a standard wood sample with no variation in size (including depth). So, in essence, what it’s saying is that given a certain sized sample of wood, when a force is applied to it directly in the center of the sample with and equivalent force of X newtons (or PSI), it will cause rupture.

      In practical terms, the easiest thing I can say would simply be to take a known wood in a known working application (some pre-existing piece of furniture) and try to extrapolate on its known MOR data into other sizes and species.

  5. Para Koirala May 25, 2018 at 2:36 pm - Reply

    does 0.075 makes sense for the MOR of LVL?

    • Eric May 29, 2018 at 2:48 pm - Reply

      No, it does not. You need a unit of measurement with that number!

  6. naimatullah April 18, 2018 at 6:12 am - Reply

    what is the modulus of rupture of orange tree?

  7. p.savarimuthu raja p.raja September 13, 2017 at 5:42 am - Reply

    Eric pls reply

  8. p.savarimuthu raja p.raja September 13, 2017 at 5:40 am - Reply

    I need one question Madagascar pine and newzealand pine MOR and MOE standard

  9. Sakura Chan March 15, 2017 at 12:07 pm - Reply

    so thats means the higher the MOR value, higher the wood strength. Is it sir? because I’m still confuse. Thanks for the reply.

    • ejmeier March 17, 2017 at 5:37 pm - Reply

      Yes, higher MOR numbers mean stronger wood.

  10. Eric February 25, 2013 at 5:15 pm - Reply

    From a quick sort, it looks like the highest MOR is African Blackwood, with Bulletwood and Wamara coming in second and third.

  11. sea February 25, 2013 at 5:11 pm - Reply

    sir, which wood has the highest modulus of rapture count and that too in Mpa?

Leave A Comment