Elco Tap-Flex Fasteners

Elco Tap-Flex
Elco Tap-Flex Fasteners

Increased thread engagement with strength and ductility

These thread-forming screws are dual heat treated, self-tapping fasteners that provide the strength, ductility, and resistance to embrittlement failures required in critical curtain wall and dissimilar metal applications.

Tap-Flex® screws are threadformers with the patent-pending E-form® segmented thread profile. This design improves both installation and in-place performance:

  • Decreases thread-forming torque, easing starting and placement
  • Overcomes friction build-up and reduces drive torque
  • Increases thread engagement, so it resists back-out and loosening caused by vibration or thermal changes

Features and Benefits

  • Eliminates thread-tapping operations
  • E-Form® configuration overcomes friction build-up and reduces drive torque
  • Roll forms own work-hardened thread to resist loosening cause by vibration or thermal changes
  • Provides enhanced pull-out performance
  • Well-suited for metal applications such as steel and aluminum
  • Flex Technology heat treat provides required strength and ductility
  • Virtually immune to delayed embrittlement failures
  • Stalgard GB coating provides 1000 hours of salt spray resistance (per ASTM B117)
  • Accept standard nuts and washers if required


  • Diameters: 3/8", 1/2", and 5/8"
  • Lengths: 1-1/2", 2", and 2-1/2"
  • Head Style: Hex washer
  • Threads: E-Form five-lobe thread forming
  • Material: Alloy steel
  • Finish: Silver Stalgard® GB coating
  • Grade 5: meets ASTM A449 specifications (120 ksi strength)

Elco Tap-Flex Part Numbers

3/8" Diameter, Hex Washer Head

1/2" Diameter, Hex Washer Head

5/8" Diameter, Hex Washer Head

Other Elco Fastener Lines