On 10/3/2011 5:06 PM, dpb wrote:
> On 10/3/2011 12:38 PM, SonomaProducts.com wrote:
>> see pins in both sides of the joint. One of my gripes with floating
>> tenons is that unless you do pin both sides it does not have the same
>> mechanical integrity asa pinned traditional M&T joint.
>
> I recall FWW did a mechanical destruction lab test(+) a number of years
> ago. W/O looking it up, my recollection is that the difference was
> essentially noise; it certainly wasn't any major difference.
Exactly:
1. Half Lap = 1603 lbs to failure
2. Bridle = 1560 lbs
3. Splined Miter = 1498 lbs
4. 3/8" M&T = 1444 lbs
5. 3/8" Floating Tenon = 1396 lbs
6. Miter = 1374 lbs
7. 3/8" Wedged M&T = 1210 lbs
8. 3/8" Pinned M&T = 1162 lbs
9. 5/16" M&T = 988 lbs
10. Beadlock = 836 lbs
11. Dowelmax = 759 lbs
12. 1/4" M&T = 717 lbs
13. Pocket Screw = 698 lbs
14. Domino = 597 lbs
15. Biscuit = 545 lbs
16. Butt 473 lbs
17. Cope & Stick = 313 lbs
18. Stub Teneon = 200 lbs
>
> (+) They manufactured various joints from simple lap to full M&T in
> their shop and took them to a uni lab (I want to say Case Western) where
> the loading tests/measurements were done in one of their labs. It was
> pretty well done as opposed to some of the writer-submitted homebrew
> setups that often lack either control or decent measurement techniques,
> etc., ...
Answers, in advance, to the next previous statements made in support of
the contention:
Depending upon the grain direction of the traditional tenon, a floating
tenon can be stronger.
Pinning the M&T joint actually made for a weaker joint.
Wood, properly glued, tends to fail at the wood and not the glue surface.
No glued joint will not last "forever".