DST Thread-Forming Screws for Plastics

These thread forming screws with dual spaced threads allow increased thread engagement in softer thermoplastics.


The high thread height and wide thread spacing of the DST (Dual-Spaced Thread) fastener allows increased thread engagement in softer thermoplastics, increasing resistance to pull-out and improving product performance.


  • High thread with a 30° flank angle
  • Smaller minor diameter
  • Greater shear area
  • Shank slot for thread-cutting can be added


  • Requires lower driving torque
  • Reduces cracking of boss
  • Allows use of smaller bosses
  • Increases thread engagement
  • Increases resistance to pull-out

Design Guidelines

  • Thread Style: High thread with a 30° profile and low thread with 60° profile
  • Head Styles: Pan, hex, flat, oval, hex washer
  • Drive Systems: All styles available; TORX PLUS® Drive System recommended
  • Point Style: Blunt, gimlet, pilot