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If you are really interested in weight saving what we really need are aluminum high strength imperial nuts 1/4",5/16".3/8".1/2"
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That's a big ask Vibrac. Which "Imperial" threads were you anticipating, BSF, Whitworth, BsCy, UNF, UNC, Admiralty Fine, BA, oh, sorry, BA is actually Metric, my mistake.If you are really interested in weight saving what we really need are aluminum high strength imperial nuts 1/4",5/16".3/8".1/2"
Douglas tended to use 25 TPI in the early years because then you HAD to buy them from the factory. Very clever. I would be a big fan of Titanium spindles and fork nuts if they were available.BSF would do fine (Pun not intended)
The Phils seemed to like them and I note so did Douglas I never know what to expect when I get to a Triumph I guess (tho I havent touched one in years) BSA are the same.Some people of oriental bike engineering bent say they often have different metric threads to EU ones so metric is not imune
Or otherwise when finding difficulties while trying to get exact info about stuff this secrecy about trade knowledge may widely produce the attitude of "that´ll do . . . " - with consequences to the affected objects ?
That's true now, but it isn't true for bikes made before the mid-1960s. Prior to unifying under the ISO banner, each country had its own version of metric, including the Japanese JIS. Although in most cases the diameters, pitches, and A/F head sizes were the same, there were some notable differences to catch the unwary. Also add to the list the German Löwenherz, which are metric fasteners but with 53° 8′ pitch angle and commonly used in places where the British used BA. Bosch magnetos through at least the 1920s used Löwenherz fasteners.Oriental metric threads are standard as in Europe
Are you sure about that? Did you actually measure the profile with a microscope or comparator? It's actually pretty difficult to do with reasonable certainty with screws that small, and if you assumed that since it's metric it had 60 degrees it would have been very easy to think you saw 60 degrees.Never heared about Löwenherz fasteners, and I got a BMW from 1928 with Bosch Magdyno. Certainly they had some M 4,5mm and 5,5 mm screws, M 3.5mm electrical norm screws, but these are common 60 degrees profile.
It actually makes a lot of sense. Once the smooth progression of, say, drill bit sizes was decided on, having a machinist ask the tool room to give him a #47 bit is a lot less prone to error than asking for a "zero point zero seven eight five inch" bit.And that with smaller size at higher numbers - what sick brain has come up with this logic ??
Never heared about Löwenherz fasteners,
Despite living in Germany, the German Löwenherz thread system came as a surprise to oexing, so I hesitate to think how he will react when he learns about the ß, ö and Ö letter drills, to name just a few (the Ö drill bit, of course, being 0.001" larger than the ö).Gentlemen, what no mention of 'letter drills'?