Thread Forming Screws

The Tappex TPX thread forming screws (not thread cutting) are designed to be used in most thermoplastic materials. These screws can be installed into drilled or moulded holes in a wide variety of applications. Tappex TPX screws are produced by cold forging, not machined from bar or wire and therefore have good inherent mechanical properties with minimum residual stress material into which it is being installed.

Thread Forming Screws - Features

  • Range of diameters and thread lengths.
  • Philips or Recessed Star Drive.
  • Hardened steel with a zinc and clear passivate.
  • Stainless steel 303 grade.
  • 30 degree thread flank angle offers the following benefits:
    • Reduced installation torque.
    • Reduced potential for over tightening.
    • Reduced stress induced in the plastic. (care should be taken with notch sensitive plastics)
  • With care the TPX screw can be re-installed multiple times.
Thread Forming Screws Screw and Hole

Thread Forming Screws - Design Considerations

For successful installation and application a number of factors should be taken into consideration:

  • Hole size and design - recommended hole geometry available from Tappex (See ETP 45 downloadable from Tappex website)
  • Type and grade of Plastic.
  • Boss wall thickness – to withstand installation forces and maximise performance.
  • Installation depth
  • Required application and strip out performance.

For advice, please contact our Applications Engineering Department with your specific requirements.

Product information

  • The part number is prefixed 069 followed by diameter and length, subsequent coding relates to type, material, finish etc. Please discuss your requirements with us.
  • Available in diameters 2.5, 3.0, 3.5, 4.0, 5.0, and 6.0mm.
  • Lengths from 6-22mm (2mm increments), 25-50mm (5mm increments).
  • Materials: Hardened Steel, Zinc and clear passivated or Stainless Steel (303 grade).
  • Available in Pan Head style, Phillips or Recessed Star Drive.
  • Refer to Tappex for availability and advice, ETP45 for further details of Dimensions. Hole Design recommendations and Features. See downloads.


The following are downloads relating to the Thread forming screws range, although a downloads may also be applicable to other product ranges. General information can be found on our downloads page.

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