Who Knows About Helicoils?

[Chuck S.]

You can buy helicoil kits which have an installer, a tap, and several helicoil inserts. For a 1/2"-13 kit, the inserts are 1/2" in length, which would be enough steel thread length to develop the full strength of the fastener. Question: What can you do if you have a deeper threaded hole, say 1" deep, in a weaker material like aluminum? Can you buy longer inserts in a given size? Where do you find them?

Chuck Sangerhausen

[Craig S.]

Re: Who Knows About Helicoils?

Chuck - I have never seen longer Heli-coils, but I have actually stacked two in a deep hole, turning one down on top of the other. It seemed to work fine....Craig

[Joe L.]

Re: Who Knows About Helicoils?

Craig and Chuck-----

Yes, as far as I know, longer Heli-Coils are not available, although they may be to industrial customers. In any event, I've stacked two of the standard size, also, and had no problem. To be honest, I don't know if this is actually necessary, even in aluminum, but it makes me feel better.

[Chuck G.]

Re: Who Knows About Helicoils?

While we're on the subject of helicoils, I'll ask if anyone has ever seen a "fine thread" helicoil? I've never seen one....always coarse thread, 1/4 x 20 instead of 1/4 x 28 and so on. Do fine thread inserts/kits exist? Chuck

[Joe Fisher]

Re: Who Knows About Helicoils?

Yes they do. I own an auto parts store and stock SAE fine thread Helicoils from 1/4 to 1/2". If you can't find them locally, email me. Also, fine thread coil kit are more expensive then coarse, because they use a special installation tool.

[Doug Flaten]

Re: Who Knows About Helicoils?

I believe they do have some longer sizes. I inquired about them last year at a nut and bolt supply shop. However, no one seemed to stock them and due to the long delivery, I took their advice and stacked them using thread lock on them. Doug

[Chuck S.]

Aluminum Bell Housing

Joe,

Some moron must have pulled my engine or transmission and put it back; one hole in my aluminum bell housing is completely stripped, and a second is partially stripped.

The General must have trying to compensate for the idiot factor by installing 1 3/4" bolts in a 1" hole; there was going to be a WHOLE LOT of noise and vibration before the transmission fell out. That's why I think I will just helicoil all four holes, two inserts per hole, and be done with it.

The "stacking" idea had occurred to me, but I wasn't sure how it would work, since the end where the "tang" breaks off doesn't leave a nice square end for the next insert to butt up against. Since the wire ends are self-aligning in the hole, I suppose the joint "gap" would have the same effect as a "pit" below the surface of the thread, and would not affect its function.

I did find kits in McMaster-Carr's (old) catalog with 1/2" NC inserts that were 3/4" long, but that doesn't completely fill the hole either. Chuck G., if there aren't fine inserts right beside the course inserts, your store is not well stocked. You might try McMaster-Carr (Look what I just found. See post below)

Chuck Sangerhausen

[Chuck S.]

GUYS, CHECK OUT THIS WEBSITE...

In trying to find if McMaster-Carr had a website for Chuck Gongloff, I guess I solved my problem. McMaster-Carr's offering has increased considerably since the old catalog I have. It looks like they have ALL their stuff offered online too. This website has real potential.

I clicked "helical inserts" under "fastening and sealing" and they have 1/2"-13 inserts up to 1" long. They also have "tangless" inserts for sizes under 1/4"-20. Kewl.

Chuck Sangerhausen


McMaster-Carr Supply Company

[Chuck G.]

Re: GUYS, CHECK OUT THIS WEBSITE...

Thanks for the info. I've bookmarked the website. I have never seen a fine thread helicoil in any local auto parts store. I'm not just talking about Pep Boys, etc., I'm talking "real" stores. I have been told that they do not exist. I don't use helicoils too often, but it's nice to know that they are available, and I won't look or sound like a "fool" if I ask for them. Thanks. Chuck