S-90434A177 Length 3/8" Tapping Screws

Key Features & Benefits at a Glance

• Superior holding power in plastic materials due to the Tri-Lobe shank design that displaces material to form strong, reliable threads without pre-tapping.
• Enhanced corrosion resistance provided by the zinc-plated steel construction, ensuring long-term durability in various environments.
• Efficient and secure installation with the Phillips No. 1 drive, reducing cam-out and allowing for high-torque application with standard tools.
• Clean, flush finish achieved with the standard flat head and 82° countersink angle, ideal for applications where a smooth surface is critical.
• Optimized for plastic assembly with a blunt tip and fully threaded right-hand design, minimizing stress cracking and ensuring consistent, full-length engagement.
• Reliable performance and compliance meeting RoHS 3 and REACH regulations, ensuring safety and environmental standards for global supply chains.

Professional Applications & Engineering Value

These No. 4 TRS thread forming screws are specifically engineered to address common challenges in plastic assembly, such as material cracking and stripped threads. The zinc-plated steel material offers excellent strength and corrosion resistance, while the Tri-Lobe shank cross-section and thread forming method create tight, secure threads in plastic substrates without generating chips. This design reduces installation torque and provides superior resistance to vibration loosening, making these flat head screws ideal for electronics enclosures, automotive trim, and consumer appliances where a reliable, flush finish is essential. The combination of a Phillips drive and specified No. 37 drill bit ensures quick, efficient assembly in high-volume production environments.

Specification Summary & Compliance

This 3/8" length screw features a thread diameter of 0.112" with 20 threads per inch and a standard flat head profile. It is designed for use with a No. 37 drill bit (0.104" diameter) and an 82° countersink angle. The screw conforms to common inch-series tolerances for thread forming types and is fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, ensuring adherence to strict environmental and safety standards.