Thread cutting (or forming) fastener for CFR PEEK

[prdave00]

Anybody with experience using a self cutting/tapping thread in carbon fiber reinforced PEEK (450CA30). I called the resin mfg, Victrex, and they were no help - they don't have any technical files for this application. I tried a couple manufacturers of fasteners to join plastics, such as Acument, but they were unresponsive. Also tried Fastenal, but they could not advise me and instead promised me samples to try out (which I never received). Unfortunately technical guides seem to be resin and/or resin manufacturer specific such as this from DuPont or BASF.

I figured I should try here for some tribal knowledge. Based on research, I'm leaning towards self cutting threads, over self forming, as they tend to be for high modulus and/or reinforced thermoplastics. The fasteners will be for permanent assembly. I can't use threaded inserts, molded in or otherwise. I'm open to "special" thread forms like assymetrical threads, etc. to prevent reversal.

Any help/guidance would be appreciated.

 

[Pud]

Try these for thread forming:

http://www.acumentnorthamerica.com/ptthreadforming.asp

or these for thread cutting:

http://www.acumentnorthamerica.com/duropt.asp

(I assumed you are in North America - if not, Google 'PT Screws')

Cheers

H

http://www.tynevalleyplastics.co.uk

Why be happy when you can be normal?

 

[CoryPad]

Good suggestions from Pud, other good parts to consider are Remform and Plastite from Reminc:

http://www.reminc.net

 

[mcgyvr]

A general rule is thread forming screws for materials with a flexural modulus of 150K-400K PSI and thread cutting for 500k-2 million psi.
So for your material with a FM of 2,930,000 psi thread cutting is the proper choice. And yes DuroPT is an excellent choice.

 

[prdave00]

Thanks for all the direction. As I stated in my OP I've had poor luck dealing with Accument directly or distributors like Fastenal. Any leads on how to get my hands on some Duro-PT screws would be much appreciated.

 

[mcgyvr]

Fastenal is typically a great company.. I hate to say it but..People are really busy/overworked now a days due to huge labor cuts.. Patience is needed now more than ever. Try them both one more time.. We actually use Fastbolt and have been very happy with their level of service.

Heck you can always just order up some "type 25" screws from Mcmaster Carr..


Just want to make sure you know that a pilot hole/boss is required as these are not self drilling screws.