Author Topic: Altette Horn thread size  (Read 665 times)

Online Rex

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Re: Altette Horn thread size
« Reply #15 on: 21.11. 2019 16:30 »
Yes - but Across the Flats spanner jaw size Rex, not shank diameter  . . .

I don't know if I'm being particularly thick today, but 4BA is roughly 6.5mm across the flats, and 1/4 UNF is roughly 11mm. :!
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Online groily

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Re: Altette Horn thread size
« Reply #16 on: 21.11. 2019 16:49 »
And yup again DuTch, 'tis very true!
 
There is quite a lot of stuff that's a real pain on some of the classic 'Metric Machines' too, especially a tendency to use 7mm and 9mm, often at 1mm pitch. Your average supplier won't have any of that, is for sure. Not always that easy to find threading tackle for some of the different pitches they used down in the 2.5 to 4.5mm area either.
But  . . . at least metric spanners fit all metric bolts, even if the heads are often a size smaller than you'd expect for the shank.

It's not just 'continental' makes either - I cursed for hours when I broke the heads off a couple of undersized 12mm AF (but M8 shanked) seized exhaust header pipe retainer bolts on my XJR Yam a while back. Absolute nightmare to sort out with the engine in the frame, and I ended up making new studs and brass nuts at 13mm AF, which will be a lot easier to get off next time. (Bit like the ongoing sump plate discussion  on here . . . Why the heck do people use bolts & setscrews in places where they are almost guaranteed to cause trouble down the line?!) Little Things that can Cause Big Grief, when the manufacturer's consideration only extends to the initial assembly of a new part in a clean factory environment.
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Bill

Online groily

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Re: Altette Horn thread size
« Reply #17 on: 21.11. 2019 17:06 »
Not thick at all Rex, it's just that these things are designed to confuse!

1/4 inch bolts in UNC and UNF take 7/16th AF spanners - that's yer 11mm near enough - across the jaw. You're dead right. They don't take a 1/4 AF weapon.
But 4BA bolt heads will take 1/4 inch AF - across the jaw - spanners.

A Whit form spanner is sized according to the bolt diameter not the width of the hex head and so the sizes are always miles 'smaller' than spanners for US-type fasteners. Hence the ref to 3/16 Whit or 1/4 BSF being pretty close to 7/16 AF.
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Bill

Offline duTch

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Re: Altette Horn thread size
« Reply #18 on: 21.11. 2019 22:17 »

 
Quote
......There is quite a lot of stuff that's a real pain on some of the classic 'Metric Machines' too, especially a tendency to use 7mm and 9mm, often at 1mm pitch.....

 I was fixing something for a friend and needed a 7.0mm 1.0 bolt and was surprised the bolt shop had "em in one length ~2"- the guy said they something to do with bicycle seat post
 Ok- I don't want to hijack the horn thread...
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Started building in about 1977/8 a on average '52 A10 -built from bits 'n pieces never resto intended -maybe 'personalised'
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Online TimK

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Re: Altette Horn thread size
« Reply #19 on: 08.12. 2019 21:58 »
Hi Everyone

following up on my original post, I gave up trying to find a suitably threaded locknut ( I though taffthehorn would be my best bet, but he didn't get back to me), but my brother managed to find a tap for me (he makes stuff for aircraft and they use some seriously weird threads in that industry), so I'm going to tap another lock nut to the correct thread.

Cheers

Tim
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Tim Kerridge
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Offline duTch

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Re: Altette Horn thread size
« Reply #20 on: 08.12. 2019 23:38 »

 So what thread did you end up with ?

 Totally unrelated, I needed a M12 *square* nut for a doo-dad for a wing-wong I was making, but gave up and made one  *bright idea* from 10mm flat bar  *work*, (various websites showed them to no avail  *pull hair out*)


   
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Started building in about 1977/8 a on average '52 A10 -built from bits 'n pieces never resto intended -maybe 'personalised'
Have a '74 850T Moto Guzzi since '92-best thing I ever bought doesn't need a kickstart 'cos it bump starts sooooooooo(mostly) easy
Australia

Online groily

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Re: Altette Horn thread size
« Reply #21 on: 09.12. 2019 08:45 »
Just to say, a bit late in the day, sorry! - that 9/16" x 32 tpi is an available size. I was on Tracy Tools' site the weekend looking for 19/32nds x 32 - which isn't listed and maybe doesn't exist - and saw 9/16ths (which I do have) is still there. (55°, if it matters, which at that size it probably doesn't, much.)
https://www.tracytools.com/taps-and-dies/whitform-taps-dies?page=2


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Bill

Online TimK

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Re: Altette Horn thread size
« Reply #22 on: 11.12. 2019 22:15 »
My brother is sending me a 9/16 x 32 UNS which he got at mates rates due to the amount of stuff his company buys. I saw the tap at Tracy tools but baulked at paying 9 pounds for a tap I'll probably only use once!
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Tim Kerridge
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