From time to time, the relative strength of wood species is discussed here at HBA. I recently ran across the following video from Fisher Flying Products.
Below I have transcribed their results, which I find questionable. Although the weight of the test samples is mentioned, interestingly, there was no mention of the relative strength-to-weight ratios. There are some obvious problems (consistency in placement of the load and small sample size) although I cannot account for all of the tests exceeding Sitka Spruce's strength-to-weight ratio (pine in particular). If Northern White Pine truly performs 30% better than Sitka Spruce, I expect the aircraft industry never would have used Sitka.
Below I have transcribed their results, which I find questionable. Although the weight of the test samples is mentioned, interestingly, there was no mention of the relative strength-to-weight ratios. There are some obvious problems (consistency in placement of the load and small sample size) although I cannot account for all of the tests exceeding Sitka Spruce's strength-to-weight ratio (pine in particular). If Northern White Pine truly performs 30% better than Sitka Spruce, I expect the aircraft industry never would have used Sitka.
Species | Specific gravity | Load carried | Ultimate stress (Fb) | Strength-to-weight | Comments | |
Sitka Spruce | as-tested: ANC-18: | 0.415 0.40 avg., 0.36 min. | 41.55 lb 37.30 lb (calculated) | 10,471 psi 9,400 psi | 107% 100% (control value) | result closely matches book value when corrected for higher specific gravity |
Northern White Pine Eastern White Pine | as-tested: ANC-18: | 0.395 0.38 avg., 0.34 min. | 47.85 lb 34.52 lb (calculated) | 12,059 psi 8,700 psi | 130% 97% | ANC-18 values listed are for EWP; both NWP & EWP are Pinus strobus |
Yellow Poplar | as-tested: other source: | 0.519 0.37 - 0.59 | 50.90 lb 40.47 lb (calculated) | 12,828 psi 10,200 psi | 105% 83% | not listed in ANC-18 |
Douglas Fir | as-tested: ANC-18: | 0.447 0.51 avg., 0.45 min | 46.45 lb 45.63 lb (calculated) | 11,706 psi 11,500 psi | 111% 96% | performed 15% better than expected despite low specific gravity |
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