Can a helicoil from side "A" take a screw/bolt from side "B"?

I have a situation where I need to screw into some aluminum.

Can a helicoil be installed at the bottom of a deep hole, or even on the other side of a deep counterbore? Say I've got two parts:

\ ------ ----- \ |_ _| | \ | | | ------------ ------- ------------ ------- / Z Z | / Z Z | ------- ------- / And where the 'Z's are, is threads. It's aluminum, and it's made of one piece, to be a clamp that looks like a fat snap ring. (to the left, out of the picture, there's a large circle. I've hinted at it here.)

So I either need an installation tool that will go through the thru part to install the HC, or install it from the bottom, which would make it backwards to the screw.

Can a helicoil be installed from one side and take a screw from the other side? Especially one that doesn't need a terribly expensive insertion tool?

Of course, other ideas are welcome - I'm kinda thinking Keensert, but do they work backwards? I'd have to put more meat on the thread end, but that's not a problem - It only exists on paper so far. :-)

And I did a search (just in s.e.m and r.c.m), on "keensert" and there was a thread where somebody mentioned yet another kind of insert; if anyone wants to give me a pointer to them (if they fit the bill, of course) I'd appreciate it. :-) Since it's a new widget, I don't think I'll need Loctite thread goop quite yet. ;-)

Thanks, Rich

Reply to
Rich Grise
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[Hobby list deleted]

A counterbored hole is not the natural home of a helicoil. They tend to have a drive wire which needs to be broken off at the surface.

What you need here is a solid insert, threaded externally and internally, which is staked into position at its top surface.

There are several commercial implementations. No, I am not going to look up names for you.


Brian Whatcott Altus OK

Reply to
Brian Whatcott

"Rich Grise" wrote: (clip)Can a helicoil be installed from one side and take a screw from the other side? Especially one that doesn't need a terribly expensive insertion tool? (clip) ^^^^^^^^^^^^^^^^ The last step in installing a Helicoil is breaking off the drive tab at the bottom. Ordinarily the broken end doesn't matter--any burr that's in the way just gets pushed aside by the screw (if it even reaches that deep.) But you would be trying to start a thread, deep down in the hole, and there is a possibility that the burr could prevent the thread from starting.

Here's what I would suggest: Make an insertion tool out of a piece of All-thread, by filing or sawing the end to engage the insertion tab. That will put the burr at the exit end of the thread, where it won't matter. Also, All-thread is much cheaper than an regulation insertion tool. The real insertion tool is a tad smaller in diameter, so that the driving torque collapses the threads a little, making insertion easier. So I would use a little lubricant during insertion. (Come on, guys, get your minds out of the gutter.)

Reply to
Leo Lichtman

Rich Grise wrote in news:

There are inserts that are open on both ends, and have flat screwdriver slots in the ends. I can't think of the name of them though.

Reply to

Rich Grise wrote in news:

Found em.... E-Z Lok In the main page picture, it's the type on the left.

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