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Helicoil Help!

Hi all,

I've just taken the head & barrels off my old Honda commuter bike, and found some previous mechanic (who has since left the country, fortranately for him) has stripped the threads on one of the head studs.

Does anyone have an M10x1.25 helicoil/recoil etc. thread repair kit? I can buy the inserts off ebay cheep enough, but the whole kit is quite expensive.

My local dealer can do the kit for =A331 + VAT, that's a walk in off the street, Mr Nobody type price. The place my company has an account with can do it at a special trade price of =A329.95 + VAT. Helpful eh?

Please let me know if anyone is prepared to sell me a kit, or loan one out for a price, or has a lead on a sensible dealer.

Thanks,

Zed

Reply to
zedbert
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Got an M10 tap, pretty sure it's 1.5 pitch, I'll check later & report back if I'm wrong. Also it's spiral flute, not the easiest to use by hand. The tap is the one thing you really need, the rest can be improvised.

Tim

Reply to
Tim Leech

report

improvised.

....ar but if he is putting in an M10 x 1.25 helicoil, the tap will be bigger than M10 by twice the thickness of the trapizoidal helicoil wire from which the 'spring' is wound. Measuring my 6mm helicoil tap it is 7.38mm o/d.

I would expect the 10mm x 1.25 pitch helicoil tap to be about 8.467 (core diam) plus 3.0672 (4 times the depth) plus a 'fit' allowance. So about 11.6 mm o/d

Have you considered making a 'stepped stud' so that you can use a standard tap to rethread the rogered hole - so maybe 12mm at one end and reducing to 10mm for the other ?

AWEM

Reply to
Andrew Mawson

J&L sell the V coil taps for about =A38 and the inserts are =A32 for 10, plus vat and postage I guess. Page 140 of the online catalogue.

Stu G

Reply to
stooby-doo

Just checked, the one I have is M12 x 1.5, the OD is 11.9 mm

Tim

Reply to
Tim Leech

Oh no it isn't, just realised my own typo. It's **M10** x 1.5, OD 11.9mm

I do have an M12, but that's x 1.75 and 14.4 OD

Tim

Reply to
Tim Leech

8.467

allowance.

...ah ...that explains that then, I couldn't understand how the helicoil itself had a negative thickness

AWEM

Reply to
Andrew Mawson

Thanks ever'one!

Have ordered the tap and inserts from J&L. Managed to resist most of the other stuff on offer till I got to the ver' last page of the sale catalogue and found metric cap head on sale. Bugger. Had to order a few LOL

Next silly question: what size is the tapping drill? or what is the forumla to work it out?

Cheers,

Zed

Reply to
zedbert

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