Thread Forming Screw Design Guide Considerations

Fastening plastics using standard self tapping screws frequently causes assembly problems. The plastic material is liable to burst due to stresses that build up in the assembly. Inserting the screws into metal inserts overcomes the problems but adds to the procurement and assembly costs.  

TR Fastenings range of thread forming screws are specifically designed to provide reliable fastener joints in a wide variety of plastic materials now in use. This document sets out for designers and production engineers the data necassary to achieve optimum assembly. It is based on the practical testing of the screws in the laboratory and the company's experience of their extensive use in industry.   

TR Fastenings Polymate family of threadforming screws:


Polymate 30  

Polymate 30 is a round bodied single start screw with a 30o thread angle and 8o pitch angle for use in thermoplastic applications and some thermosets.



Polymate 40  

Polymate 40 is a round bodied Metric twinstart screw with a high helix developed for the plastics industry.



Polymate 45  

The Polymate 45 is a trilobualr bodied single start screw with a 45o angle thread form designed for installing into a wide variety of thermoplastics including glass filled Nylons and modified Polyphenylene oxide.



Polymate 60  

The Polymate 60 is a trilobualr bodied single start screw with a 60o angle thread form designed for installing into Nylon, Acetal, ABS and some glass filled nylons.



Note: Due to the fact that fastening applications differ greatly, the above information is for guidance only and is correct to the best of our knowledge. The customer must satisfy themselves with the performance of the fastener and validity of the data. TR Fastenings will not be held responsible for any failure that may occur from the use of this information.