S-99512A661 Length 3/4" Tapping Screws

Key Features & Benefits at a Glance

• Superior holding power in plastic thanks to the Tri-Lobe shank design that creates secure, vibration-resistant threads without pre-tapping
• Enhanced corrosion resistance provided by the Black-Oxide steel finish, ensuring long-term durability in various industrial environments
• High-torque driving capability with the Torx T10 drive, reducing cam-out and tool slippage for efficient, damage-free installation
• Optimized for plastic assembly with a thread-forming (TRS) design that eliminates chip formation and ensures strong, reliable fastening
• Streamlined installation process using a standard No. 37 drill bit (0.104" diameter), simplifying hole preparation and reducing assembly time
• Full 3/4" thread engagement for maximum grip length and distribution of stress in plastic materials
• Compliance with major environmental regulations including RoHS 3 and REACH, making them suitable for global supply chains and sensitive applications

Professional Applications & Engineering Value

These Black-Oxide Steel TRS plastic tapping screws are engineered to solve common fastening challenges in plastic assembly. The thread-forming design with its Tri-Lobe shank cross-section displaces material to create strong, permanent threads without generating chips, preventing contamination and structural weakness in delicate plastic components. This is critical in electronics enclosures, automotive trim, and consumer products where material integrity is paramount. The Torx T10 drive provides superior torque transfer compared to Phillips or slotted drives, minimizing the risk of head stripping and ensuring consistent clamp load. Combined with the corrosion-resistant Black-Oxide finish, these screws deliver reliable, long-lasting performance in demanding industrial environments, reducing maintenance and failure rates.

Specification Summary & Compliance

This No. 4-20 x 3/4" screw features a right-hand thread with an approximate 20 threads per inch and a 0.112" thread diameter. It is fully threaded with a blunt tip and a standard pan head profile. Manufactured as a Type TRS (Thread Rolling Screw) for thread-forming applications, it is designed for use with a No. 37 drill bit (0.104" diameter). The product is confirmed to be RoHS 3 (2015/863/EU) Compliant and REACH (EC 1907/2006) Compliant.