Design of rivets to fasten plastics?

[hhaenlein]

I'm considering using a rivet to hold two plastic moldings together, and to act as a pivot between the two halves. Can anyone point me to a resource that would help me engineer such a rivet? Material would probably be brass, main load that worries me is tensile. I'm thinking that a shouldered rivet, with a semi tubular clinch feature would work well - but what is the tensile load that I can expect such a rivet to withstand?

Thanks!

 

[insideman]

It would probably help if you would provide more detail about your requirement. Diameter, thickness, type of plastic, expected loads, etc.

Meanwhile, I have used eyelets for fastening plastic parts and allowing them to pivot. Even for quite small sizes the plastic will fail before the eyelet fails.

Look up Stimpson, give them a call, You will find them quite helpful.

 

[Daleyfish]

Yes more info is needed. However care should be taken to avoid the high stress concentration inherent in most riveting techniques. Large dia. head and reinforcing washers are good to distribute stresses, and all sharp corners should be broken or radiussed. The sholes should provide at least a .010in (.254 mm) clearance on the rivet shank to ease assembly and compenstate to tolerances and coefficient of thermal expansion. Aluminum rivets are preferred over steel, since the AL. will more readily deform under hight stress. Using a shouldered rivet is a good idea and will also keep control stresses by limiting the compressive forces tat can be applied to the plastic part.

 

[hhaenlein]

Thanks for the feedback. I'll be specifying a standard semi-tubular rivet, clinched over a washer + a short length of tube + a washer to give me the pivot I'm after. But I'm still having problems getting even approximate figures for the tensile failure performance of semi-tubular rivets. I'll have to get hold of some & test them myself, unless someone knows of a handy website or booklet.