ELCO ESU350 3/8"-16 x 4" 9/16" Hex Washer Head Silver Stalgard® SUB Coating Tap-Flex™ Thread-Forming Structural Screws (250/Box)
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
Specifications
- 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)