What is apply torque on NORYL and DELRIN material? 1

[assitanceproduct1]

Any one know about torque apply on NORYL and DELRIN when using 2-56 and 4-40 screw. I'm appriciate

 

[CoryPad]

Is the mating internal thread the plastic itself or a metallic insert? Will the screw be forming its own threads? What is the screw material and coating? What is the screw head outer contact diameter and the mating part hole size? Be aware that the plastics will creep due to the applied compression, which will decrease the clamping force over time.


Regards,

Cory

Please see FAQ731-376 for tips on how to make the best use of Eng-Tips Fora.

 

[assitanceproduct1]

Thank Cory

There is no metallic insert, the screw be forming its own threads. The screw head contact diameter for 2-56 is .086 and the mating part hole size is .078. And for 4-40 is is .112 and the mating hole size is .099

Again thank cory

 

[CoryPad]

Are you using a standard machine thread screw to form threads? Or, are you using a thread forming screw (like TAPTITE) that just happens to have the same diameter and pitch as a standard machine thread? You should consider screws specifically designed for plastics - Textron Fastening Systems has a nice guide on their site:

http://www.fastenersforplastics.com/plastics/appguide.html

Regards,

Cory

Please see FAQ731-376 for tips on how to make the best use of Eng-Tips Fora.