alan p Posted December 26, 2021 Share Posted December 26, 2021 IF you are struggling to find the correct size have you the space and enough material to go up a size by retapping the nut portion of the fixing(8mm/5/16)? 1 Quote Link to comment Share on other sites More sharing options...
Geoff S Posted December 26, 2021 Share Posted December 26, 2021 If the bolts have a 26 tpi thread then they're probably 1/4" BSF, which would square with 6mm (1 mm thread pitch) being OK but a little loose? Quote Link to comment Share on other sites More sharing options...
Don Fry Posted December 26, 2021 Share Posted December 26, 2021 May the people who “invented” all these threads be made to sit a circle in a badly lit corner of hell, and try to match threads to nuts for eternity. Quote Link to comment Share on other sites More sharing options...
leccyflyer Posted December 26, 2021 Share Posted December 26, 2021 What does the head of the bolt look like? If it looks like the one in the link that I posted in Post #2, it's a fairly safe bet that's what you are after, since that's npt a very common bolt head type. All the dimensions can be read from that eBay item advert. Quote Link to comment Share on other sites More sharing options...
Geoff S Posted December 26, 2021 Share Posted December 26, 2021 3 hours ago, Don Fry said: May the people who “invented” all these threads be made to sit a circle in a badly lit corner of hell, and try to match threads to nuts for eternity. One of them would be Whitworth but that's one reason I now try to avoid anything but metric nuts and bolts and, as fas as is practical, hurl US sized threaded fastenings into the bin as hard as possible. Having spent many years working on both motor and pedal cycles as a hobby, the different threads (many left handed, particularly on pedal cycles) have long driven me to distraction. And don't start me on pedal cycle wheel diameters and their definitions, because that's as bad. There's a lot to be said for standardisation. 1 Quote Link to comment Share on other sites More sharing options...
Don Fry Posted December 26, 2021 Share Posted December 26, 2021 I have a well read engineer friend, who says that the origins lay, in a cutter is put in the lathe, and the gears were not altered in the tail movement, and that gives the pitch and thread profile. And it becomes the thread. And if the product is good, it becomes THE THREAD. I do metric course, unless prodded. Not a great thread, cheap profile, but functional. I have a load of other stuff in a box. Quote Link to comment Share on other sites More sharing options...
kc Posted December 26, 2021 Share Posted December 26, 2021 (edited) Another way around the problem may be to try to insert a captive nut or an M6 insert nut sold by Screwfix or B&Q to convert the fuselage part to a standard type of wing bolt. Easier than tapping to a new thread and doesnt need taps or tap holders. The inserts cut their own way in and can be inserted with an allen key. For security fit them so the head is underneath. The M6 inserts have plenty of other uses for fuselage jigs etc or in the workshop. Edited December 26, 2021 by kc Quote Link to comment Share on other sites More sharing options...
John Wagg Posted December 27, 2021 Author Share Posted December 27, 2021 (edited) Very sorry for slow responses to postings. Internet down last night and only intermittent connection currently. Have read all recent posts but have no thoughts yet. May have to do a conversion or adaption per suggestions if I cannot find appropriate bolts. Telephone people (Openreach) booked to come on the 30th Dec. ?. Hopefully will be fixed and back to normal. Regards to all. John Edited December 27, 2021 by John Wagg Quote Link to comment Share on other sites More sharing options...
John Wagg Posted December 27, 2021 Author Share Posted December 27, 2021 (edited) 19 hours ago, leccyflyer said: What does the head of the bolt look like? If it looks like the one in the link that I posted in Post #2, it's a fairly safe bet that's what you are after, since that's npt a very common bolt head type. All the dimensions can be read from that eBay item advert. Yes those look like I want but only need the bolts. The Ebay sale is a bit expensive + postage from France so not in favour yet. Bolt major diameter of mine is 6.3mm. Thanks John Edited December 27, 2021 by John Wagg Quote Link to comment Share on other sites More sharing options...
alan p Posted December 27, 2021 Share Posted December 27, 2021 If You are measuring correctly 6.3mm =1/4" imperial (6.3divide by 25.4 =.248") Quote Link to comment Share on other sites More sharing options...
PatMc Posted December 27, 2021 Share Posted December 27, 2021 @John Wagg I have a pair of these, screws & mounting brackets complete, doing nothing. They're unused but slightly grubby & the plastic is opaque white rather than translucent as the Ebay ones. If you want to try them PM me your address & I'll stick them in the post. 1 Quote Link to comment Share on other sites More sharing options...
Martin Harris - Moderator Posted December 27, 2021 Share Posted December 27, 2021 22 hours ago, Geoff S said: On 26/12/2021 at 15:35, Don Fry said: May the people who “invented” all these threads be made to sit a circle in a badly lit corner of hell, and try to match threads to nuts for eternity. 22 hours ago, Geoff S said: One of them would be Whitworth but that's one reason I now try to avoid anything but metric nuts and bolts As he is usually acknowledged to be the first person to define a standardised thread form, then he should be celebrated rather than vilified! Throw out that new-fangled metric rubbish instead and enjoy the logic of defining spanner sizes by thread diameter rather than across flats… 1 Quote Link to comment Share on other sites More sharing options...
Christopher Wolfe Posted December 27, 2021 Share Posted December 27, 2021 I have a few nylon wing bolts sourced from the US that have a 1/4" x 20tpi thread, Dubro is one typical brand. Pretty popular here in Oz so might be worth checking. Quote Link to comment Share on other sites More sharing options...
Geoff S Posted December 27, 2021 Share Posted December 27, 2021 (edited) 58 minutes ago, Martin Harris - Moderator said: As he is usually acknowledged to be the first person to define a standardised thread form, then he should be celebrated rather than vilified! Throw out that new-fangled metric rubbish instead and enjoy the logic of defining spanner sizes by thread diameter rather than across flats… Ah, so that's why I have spanners that are both 3/16" Whitworth and 1/4" BSF yet are the same distance across the flats. Edited December 27, 2021 by Geoff S Quote Link to comment Share on other sites More sharing options...
alan p Posted December 27, 2021 Share Posted December 27, 2021 now then chaps lets not throw the spanners in the corner? Quote Link to comment Share on other sites More sharing options...
Martin Harris - Moderator Posted December 27, 2021 Share Posted December 27, 2021 Yes - Whitworth used a larger head size but I believe they started using the same size as BSF during WW2 in order to save steel. Quote Link to comment Share on other sites More sharing options...
Don Fry Posted December 27, 2021 Share Posted December 27, 2021 I’ve got a big bag of spanners, and stuff, belonging to several generations of ancestors. Just bear in mind, supporters of these random thread inventors, might just get to watch their heroes match nuts to threads iin the shadows of that dark corner of hell. Quote Link to comment Share on other sites More sharing options...
Martin Harris - Moderator Posted December 27, 2021 Share Posted December 27, 2021 Where do you stand on B.A. then? It’s a metric thread based on 6mm dia x 1mm pitch for 0 B.A which decrements in pitch by multiplying each thread specification by 0.9 i.e. 1 B.A. 0.9 mm pitch. All nice and simple…diameter is slightly more complex due to losing a little of the theoretical size of pitch x 6 to rounding of the roots and crests but equally logical. Oh, and once rounded to two decimal places, the definitions were specified in imperial measurements! Quote Link to comment Share on other sites More sharing options...
Paul De Tourtoulon Posted December 27, 2021 Share Posted December 27, 2021 Well this certainly is a long shaggy dog joke, two pages so what's the punch line ?.? Quote Link to comment Share on other sites More sharing options...
Don Fry Posted December 27, 2021 Share Posted December 27, 2021 It’s that time of year Paul. There’s another thread running about hitting balls with lumps of willow. Unless sometimes it’s leather balls hitting other balls. Strange entertainment. Quote Link to comment Share on other sites More sharing options...
Geoff S Posted December 27, 2021 Share Posted December 27, 2021 1 hour ago, Martin Harris - Moderator said: Where do you stand on B.A. then? It’s a metric thread based on 6mm dia x 1mm pitch for 0 B.A which decrements in pitch by multiplying each thread specification by 0.9 i.e. 1 B.A. 0.9 mm pitch. All nice and simple…diameter is slightly more complex due to losing a little of the theoretical size of pitch x 6 to rounding of the roots and crests but equally logical. Oh, and once rounded to two decimal places, the definitions were specified in imperial measurements! I think BA was used a lot for clocks and watches. My grandfather started his clock repair business in 1878 and died when I was 5 in 1945 (we all lived at the shop). I can still remember him at his bench with a treadle operated lathe and there were boxes of BA bolt sizes in the 20s - they were really tiny - in the drawers. 2, 4 and 6 BA were used a lot in radio and TVs back in the 50s when I was repairing them and when I started modelling I used 4 and 6 BA before I standardised on metric. I suppose it's just how engineering developed. Isn't standard rail gauge 4' 8" because it matched the gauge used to haul coal behind pit ponies and that has origins even earlier? Quote Link to comment Share on other sites More sharing options...
Martin Harris - Moderator Posted December 27, 2021 Share Posted December 27, 2021 Roman carts, I believe. Quote Link to comment Share on other sites More sharing options...
John Stainforth Posted December 27, 2021 Share Posted December 27, 2021 Yes, Roman chariots that were designed to fit the hindquarters of two standard Roman horses. When the Romans came to Britain the chariot wheels created ruts in the roads - particularly their stone-paved roads - which made it awkward for any subsequent horse-drawn carriages to have different wheel gauges. Then, when railway lines were put in on the same routes it was only practical to place them over the ruts. Quote Link to comment Share on other sites More sharing options...
Paul De Tourtoulon Posted December 28, 2021 Share Posted December 28, 2021 (edited) 9 hours ago, Geoff S said: I think BA was used a lot for clocks and watches. My grandfather started his clock repair business in 1878 Maybe about time to put the subject to sleep,,, Is the other subject about a fire that's long gone out,,, Edited December 28, 2021 by Paul De Tourtoulon ashes Quote Link to comment Share on other sites More sharing options...
Nigel R Posted December 28, 2021 Share Posted December 28, 2021 On 26/12/2021 at 19:28, Geoff S said: One of them would be Whitworth but that's one reason I now try to avoid anything but metric nuts and bolts and, as fas as is practical, hurl US sized threaded fastenings into the bin as hard as possible. Having spent many years working on both motor and pedal cycles as a hobby, the different threads (many left handed, particularly on pedal cycles) have long driven me to distraction. And don't start me on pedal cycle wheel diameters and their definitions, because that's as bad. There's a lot to be said for standardisation. Pedal bike sizes are a cesspool of fashion and marketing led dumb foolery. I say that whilst being a regular cyclist and general fan of biking! Quote Link to comment Share on other sites More sharing options...
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