Stop Cracking in Plastic Assemblies — Replace Self-Tapping Screws
Stop Cracking in Plastic Assemblies — Replace Self-Tapping Screws
Cracking of plastic housings during or after screw installation is a common issue, often resulting from two primary factors:
Cracking of plastic housings during or after screw installation is a common issue, often resulting from two primary factors:
Incorrect Screw
Using standard self-tapping screws that are not designed for plastic application. The aggressive 60º thread angle induces high stress causing cracks in the plastic materials.
Poor Boss Design
If the pilot hole is too small or not properly aligned with the screw size, it can cause the plastic to be forced out during installation, increasing the likelihood of cracking.
How does REMFORM® II HS™ solve the problem?
Minimal radial tension (during thread forming process)
- The narrow tip angle (30º) and optimized pitch design reduces the radial stress and so, the problem of boss cracking.
- The Steep Convex Flank transfers most of the tightening load (F) in the axial direction (Fa), minimizing radial force (Fr) and consequently plastic deformation.
Minimal radial tension (during thread forming process)
- The narrow tip angle (30º) and optimized pitch design reduces the radial stress and so, the problem of boss cracking.
- The steep Convex Flank transfers most of the tightening load (F) in the axial direction (Fa), minimizing radial force (Fr) and consequently plastic deformation.
How CELO help you with boss design?
Pilot hole calculator
CELO's tool for screw hole design provides the hole sizes of thread forming screws for plastic assemblies. Calculate now
Application engineering support
Our Engineers can help analyze material and assembly requirements to identify the best fastening solution for your needs.