S-99397A064 Length 4 mm Tapping Screws

Key Features & Benefits at a Glance

• Superior corrosion resistance with 18-8 stainless steel construction, ensuring long-term reliability in humid or demanding environments
• Enhanced torque transmission and reduced cam-out thanks to the Torx Plus IP6 drive, allowing for higher installation speeds and fewer tool slippages
• Secure, vibration-resistant fastening in plastics achieved through the tri-lobe shank design, which forms strong threads without pre-tapping
• Consistent, precise thread engagement with a 0.79mm pitch and fully threaded design, minimizing the risk of cross-threading
• Broad compatibility with standard tools using T6 drive size, streamlining assembly processes and reducing operator fatigue
• Environmental and regulatory compliance meeting RoHS 3 and REACH standards, making them suitable for global supply chains and sensitive applications
• Optimized for plastic materials with a blunt tip and thread-forming TRS design, reducing stress cracking and ensuring clean installations

Professional Applications & Engineering Value

These M1.91 x 4mm TRS thread forming screws are engineered to address common challenges in plastic assembly, such as material cracking and loose fasteners under vibration. The 18-8 stainless steel offers excellent strength and corrosion resistance, ideal for electronics, automotive components, and consumer goods exposed to moisture. The tri-lobe shank displaces plastic material during installation, creating robust, permanent threads that resist back-out, while the Torx Plus drive ensures high torque transfer without stripping. This combination reduces assembly time, eliminates the need for additional inserts, and enhances product longevity in plastic applications, making them a reliable choice for high-volume manufacturing.

Specification Summary & Compliance

This screw features a metric M1.91 size with a 4mm length and 0.79mm thread pitch, designed for use with a No. 51 drill bit (0.067" diameter). It complies with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, ensuring adherence to environmental and safety standards. The thread-forming TRS type and right-hand threading provide consistent performance in plastic substrates, backed by precise manufacturing tolerances for reliable fastening.