Non-magnetic thread inserts

[TheKraken]

Hi! I'm a researcher who has come to you all in the past, and you've always been a helpful bunch, so thanks.

We've got a large aluminum apparatus that needs absolutely non-magnetic thread inserts. We could use phosphor bronze or titanium. The only problem is that one particular company that will not be named wants all of our arms for the inserts. something on the order of 8$ per, as they've said, which seems a little extreme to me.

Is this standard pricing for "exotic" thread inserts? Who's your favorite thread insert distributor? I don't think it's a violation of posting policy to ask the latter question, but if it is, sorry, and feel free to send me a personal message with the response, if you are so inclined.

Thanks!

 

[mrpi]

That price seems to be on-par with something like that. Since the demand is so low for them, they may be making them for you special-order. You'll still need a bunch of suitable fasteners, those may be even more expensive!

There may be hidden costs associated with the type of fastener you choose. I.E. if you choose Ti inserts and need to use Ti fasteners, you'll need some kind of anti-seize film or lubricant to prevent galling. If this is a high-vacuum application, this may further limit your choices. The un-named manufacturer may be able to supply some kind of coating pre-applied to the helical insert to provide anti-seizing protection.

The manufacturer of the insert may be able to help choose something, as they've probably been approached about this subject before.

If you only need a handful of these inserts for a prototype or whatever, eBay has some phosphor-bronze Helicoil listings. The locking ones are nice, they have a couple threads that are slightly deformed to provide vibration-loosening protection, like using Loctite.


Beat to fit, paint to match.

 

[unclesyd]

Have you tried someone like Yardley.
A little more information as to size might generate a more specific answer.

You might want to checkout the Full-Torque thread repair device. I know they make them in Al.
I'm not going to tell how much we paid for 3/4" Titanium
thread recovery devices. $250 each I couldn't hold back.
These were not the Full-Torque Device.

http://www.yardleyproducts.com/

http://fulltorque.com/

 

[tbuelna]

TheKraken,

You can easily get keenserts in 303/316 cres, if that material is acceptable.

Try Tridair or McMaster-Carr supply.

 

[arunmrao]

If you really need cheap ones,visit any scrap yard near to you,look around quite often one can get them at a fraction of cost.

Else engage your department workshop to machine a few from the rod material.

_____________________________________
"The richer we have become materially, the poorer we have become morally and spiritually." Martin Luther King Jr

 

[desertfox]

Hi Kraken

Have a look at this site:-

http://www.noblefix.com/helicoil.htm

desertfox

 

[HDS]

Pem makes AL standoffs and brass inserts. May have Ti or something else custom.

$8 each isn't that bad for something exotic. Especially if you know it will work. If you are that cheap why not tap the AL apparatus?

 

[TheKraken]

Thanks for all the help! We did actually tap the apparatus in the past. This is the third go-around of the device, so some of the threads are taking wear. There should be almost no vibration with the apparatus since, for our experiment, that would increase statistical errors. We're looking at buying sizes from 8-20 UNF up to 1/4". I expect the device will be assembled and disassembled at least twice; Once to test various pieces, and again when we're planning on engaging the experiment.

 

[drawoh]

TheKraken,

Can you increase the depth of the threads and simply forget about the inserts?

Can you use screws and nuts?

JHG

 

[hydtools]

Can you use a plastic screw?

http://www.voltplastics.com/product_listing.php?cat_id=143

Ted

 

[TheKraken]

Some of the bores are blind bore, some could use nuts instead of worrying about screw threads. I don't think we can use plastic screws, since much of the device needs to be vacuum tight, but I'd consider it none the less. I presume plastic screws are much less likely to destroy aluminum threads?

Thanks again!

 

[hydtools]

Yes, much less likely.

Ted

 

[Tmoose]

Did you mention how much thread engagement you have, and the tightening procedure? I'd kind of expect any combo to survive a few assembly/disassembly cycles.

If you can convert to "studs" in place of bolts, one wearing thread interface (screw>part) can be exchanged for another (stud>nut)