Need Heli-Coil help

68COUGAR

Registered User
I need to get one of the blower, top threads Heli-Coiled. The thread is M8-1.25 x 1.5D (I have no idea what the "D" indicates). I have the Heli-Coils (FIX-A-THRED from AutoZone). The drill required is 8.3 mm OR 21/64". What I need to know is: What size metric tap/thread is required for this heli-coil?

I'm still looking for the FIX-A-THRED website, but no luck so far.

Thanks In Advance for you help!!!!!!

68COUGAR
 
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Still need Tap Size

gldiii said:
Most of those coils take a special tap to install that comes with the coils. Looks like your coils also need an installation tool

Here is there website:

http://www.hev.com/catalog/veri/fix-a-thred.htm
George,

Thanx for the website.

Yes there is a spacial Tool to install Heli-Coils or FIX-A-THRED's. It's avail. from A/Z (with various coils) for about $32.00.

I would think that a standard metric thread, would require a larger standard metric heli-coil thread. That's just a Guess though.

On that web site, I don't see any tap sizes listed, special or regular.

68COUGAR
 
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I don't think you get what I am trying to say. The Heli-coils and other inserts require special taps that are not standard thread taps.

I beleive they are called "STI" (screw thread insert) taps and have a different size and thread shape than than standard screw taps.

This link has some more info on the Heli-coil inserts:

http://www.emhart.com/products/helicoil/techtopic/tt4.htm
 
i had the same problem with a previous SC. I bought a helicoil kit from advance auto M8x1.25, it came with the special tap, inserts, and installtion tool cost about $35. i just looked at the kit it requires a m8x1.25STI tap as glidii said with a 21/64 drill bit
 
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Thanks for Educating an Old Guy

gldiii said:
I don't think you get what I am trying to say. The Heli-coils and other inserts require special taps that are not standard thread taps.

I beleive they are called "STI" (screw thread insert) taps and have a different size and thread shape than than standard screw taps.

This link has some more info on the Heli-coil inserts:

http://www.emhart.com/products/helicoil/techtopic/tt4.htm
Thanks George, for educating this Old Guy.

It would be Sooooo simple, if common sense was the Rule!

68COUGAR
 
I have used Keenserts....

I swear by them....

They are way better than heli-coils, IMO....

Works with standard drills and taps.....
 
Actually I have often use taps to install my own helicoils I believe you need a 10mm1.25 tap to install the 8mm1.25 helicoil. I found it by checking the tap that came with my helicoil kit.
Alan
 
the-big-e said:
I have used Keenserts....

I swear by them....

They are way better than heli-coils, IMO....

Works with standard drills and taps.....

I concur a Keenset is much better than a helicoil.
 
Heli-Coil Tap

I ended up buying the Tap & Installation Tool. Nowhere on the tap does it say what the actual size is.

This is the second blower that I've had the hat threads Heli-Coiled. The first one I just bought the Heli-Coils, & hoped the machine shop would have the Tap & Tool. Didn't realize it took a special Tap. When I got the 1st. blower back & tried the had bolts, they all seemed loose to me. Actually wobbly. I'll bet they used a standard metric tap & not the special tap.

This time I went to a different machine shop (since I moved). The machinist told me that Heli-Coils do in fact take a special tap, for EVERY SIZE of Heli-Coil. He said that it's an interference fit between the tapped hole & the Heli-Coil.

Sounds like a good way to sell taps, but a lousy way to keep customers happy!

68COUGAR
 
If you're able to....

This may sound extreme, but I took my SC top and SC and drilled the holes out on a milling machine and put standard 1/2 inch bolts in there. The larger bolts hold alot more torque and if I just happen to 'drop one' its easy to replace. Also, in the 10 years I've had it this way, the threads have stayed where they're where they're supposed to be, not wrapped around the bolt.
 
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