Plastics and Injection Molding Design Reference

Design Guides

  • Plastic Joining Guide by Covestro PDF (1.6 MB)
  • Part and Mold Design Guide by Covestro PDF (4.1 MB)
  • Designing with Plastics by Gunter Erhard PDF (765.8 KB)
  • Snap-Fit Design Manual by BASF PDF (1003.5 KB)
  • Snap-Fit Joints for Plastics by Bayer PDF (2.5 MB)


Never leave an air gap between threaded insert and mating face.
Unless you absolutely must, and have tight control of installation torque, flush installations are recommended to avoid pullout. Use threaded inserts in a nut-like fashion for the best hold.