They used the hydraulic force of water.

Sorting through the data, it appears that Licaria canella (Kaneelhart) has the best crushing strength to weight ratio. (Although bamboo also ranks very high, but I tend to discount this as bamboo has so much variation between species, and the data is very patchwork and can be taken from such a wide variety of species that it may be that we end up linking the strength of one species with the weight of another, etc.)

You’re right about the USDA links, they recently changed their link structure so I’ve had to update all the links, but overlooked links in the comments. It should be updated to work now.

Hello Eric, I would like to delve further into this, as per Gregory’s enquiry ut for entirely different reason…. I have started making laminated longbows and looking into what woods are best suited. I have read your piece on this subject and fascinated by the “Bow Index” you produce relating MoR with MoE. However, as pertinent as this is it is not the whole story.

The inner laminate, facing the archer (belly), is subject to compression. The centre laminate (spine) merely flexes but the outer laminate (back) is under tension.

Woods ideally suited to spine include Purpleheart from S. America or Padauk from Africa.
Woods for backing known for their extreme tensile strength include hickory, bamboo.
Belly woods include lemonwood, osage orange, maple.

But I would like to explore what other generally available woods are also suitable, an understanding of compression strength and tensile strength as separate properties become important.

BTW, the link to the USDA wood handbook no longer works. Perhaps the Web address has been changed?

Kind regards.

Be aware that the speed of sound along and perpendicular to the grain both affect the performance of a guitar top. So strength is only a small part of the story.
Fot example, this is the reason that the grain of the wood runs along the long dimension of the guitar.

Can’t address all your questions, but the USDA wood handbook has more in-depth information on select species of woods, sitka spruce being one of them. https://www.fpl.fs.fed.us/documnts/fplgtr/fplgtr190/chapter_05.pdf

I’m building a guitar and want to make a top from Sitka Spruce and another top from carbon fiber sheet, and compare them. I know Sitka Spruce tops on guitars are typicaly 1/8″ (3.2mm) with additional bracing. Elastic (flexure) modulus of Sitka Spruce is 11 GPa. But you don’t list the tensile strength of Sitka Spruce.

I need to figure out an equivalent thickness for the CF. For example, I know Toray T700S has a flexure modulus of 120 GPa and a tensile strength of 2860 MPa. https://www.toraycma.com/page.php?id=661

Any suggestions for calculating the thickness of a CF guitar top with flexure and tensile strength equivalent to a 1/8″ Sitka Spruce top?