Luke, the claim is (to paraphrase a little "one third faster in both ripping and cross-cutting than standard toothing".
Sound too good to be true?
:U
Cheers,
Printable View
Luke, my first impulse was to nod & agree emphatically, but a small voice at the back of my head said "hmmm, there are a few examples I can think of where superior function was trumped by convenience of a bigger advertising budget". You can probably all fill in your own blanks, but one thing that springs to mind is the triumph of cassette recorders over open reel recorders - convenience whipped quality, hands down. The BMT teeth may possibly have been a 'better mousetrap', but they look a bit intimidating to your average Joe, more used to the simpler geometry of conventional fangs. They were also up against some pretty big, well-established competition, and anyone who lives under our Coles/Woolworths system knows how that can distort the free-market ideal a little! :; Magnetic tape recorders have passed into history, and that's a long-dead argument, but we may hear more of BMT teeth now that they've been resurrected. Stand by for a debate along the bevel-down/bevel-up lines. :roll:
I'll admit to a high level of scepticism myself, but also a bit of curiosity. Those square-angled teeth might not tear at a file the way the bottom of a 60 degree gullet does, so it might even be easier to sharpen this style with a poor quality flat file than a triangular tooth with a poor quality triangular file. But it might be a very long while before I try it, partly because I think it would be trickier to make teeth of a size appropriate for a backsaw, & partly because it's too much work to file in those deep gullets between the tri-tooth groups. But if someone wants to rough one out for me, I'll have a go at setting & sharpening & give it a few test-cuts..... :U
I found a interesting saw online this week that made me recall this discussion on the BMT teeth and it's modern incarnation from TFWW.
Check out this Japanese version: https://www.ebay.com/itm/131778234536
Not sure of its age but it's a bit beyond my tool budget!
Attachment 379069Attachment 379070
Certainly some similar thinking going on here!
Some shots of the TFWW version for comparison:
Attachment 379071Attachment 379072
Disston had their D17 Double Duty saw, which made very similar claims. It dates from just after WW1.
Some information on this thread:
https://www.woodworkforums.com/f152/tale-dissys-195195
I acquired another more recently, but a later version this time.
Regards
Paul