helicoil or chemical metal

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immylam
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I have threaded my bottom exhaust bracket stud in the casing on my jet, I have already tapped it out to a 10mm previously. Would it be better to get it helicoiled or is there a good chemi-metal that will hold it....or do I bite the bullet and get it welded and re-tapped? The top stud is fine.
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Muttley McLadd
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Aren't they supposed to be threaded?

Helicoil should be fine, if the thread is damaged.
CakeAndArseParty
Angry Bloke
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Helicoil or weld/retap in my opinion :D

I wouldn't trust epoxy metal in a stressed area
Je fettle - Tu fettle - Il fettle - Nous fettleons - Vous fettlez - Ils fettlent

"Broadsword calling Danny boy ,Broadsword calling Danny boy ,over "
PeteB
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Stripped the thread on mine, so tried chem metalling a stud in as a quick-fit bodge. Didn't work - the heat made the chem metal go soft and crumbly. Insert or welding is the only answer I'm afraid...
gaz_powell
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If its been tapped to 10mm and is now stripped I think it will be to big to take a M8 helicoil.
you will need to get an insert which has a thicker wall than a traditional helicoil. Welding and tapped is the best option but its an engine out to do it ....mind an insert is to if you want it perfect.

Good luck
Yanker
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Nooooo

Either get it welded (if enine stripped)

Or better (still) 'Time Sert' it. From memory M8 is a 10.8mm drill size.

chris37
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If the 10mm thread is good,I would be tempted to get a piece of 10mm studding,file the end piece until a 8mm die can be ran down the necessary length and cut off enough 10mm thread to fit in to the casing i.e. a stepped stud.
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immylam
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I already had tapped for a 10mm and drilled the chaincase to fit so putting in a 10mm stud back isn't a problem, what size would I have to drill to take the 10mm helicoil and is there enough meat in the casing to take it out to this size? Saw those time serts , quite pricey though and again don't know if I can go as far as 10.8mm.
Last edited by immylam on Tue Jan 21, 2014 10:45 pm, edited 1 time in total.
camel
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I think his 10mm thread is goosed as well chris.My m8 helicoil set has a 8.3mm tapping drill(just measured it for you so your knackered there.)
you could use a 10mm helicoil and use the stepped stud method as just mentioned.
Ive just done a similar job for a friend,his was worse as he,d tried to drill out a broken stud and veered off at a strange angle,i had to reposition the hole on a milling machine,plug it with an oversize ally stud and redrill and tap it,was a pain.
goldeneye
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beedspeed sell various stepped repair studs, some may be odd thread one end e.g. a whitworth /13mm other end, but they work. is it the casing tailpipe one? ive done one out to 11mm and made the casing hole bigger to suit,not original but works.
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