S-99397A222 Length 4 mm Tapping Screws

Key Features & Benefits at a Glance

• Superior torque transmission and reduced cam-out with Torx Plus IP6 drive for reliable, high-torque fastening
• Excellent corrosion resistance provided by the zinc-plated steel finish, extending service life in various environments
• High-strength thread forming action with the tri-lobe shank design creates secure, vibration-resistant threads in plastic materials
• Reduced risk of material cracking or stress due to the thread forming (TRS) tapping method, ideal for delicate plastic assemblies
• Broad compatibility and easy installation with a standard pan head and blunt tip, paired with a No. 51 drill bit for precise hole preparation
• Full-length threading (4mm) ensures maximum grip and holding power along the entire fastener length
• Compliance with major environmental regulations including RoHS 3 and REACH, ensuring safety and suitability for regulated industries

Professional Applications & Engineering Value

These M1.91 x 4mm thread forming screws are precision-engineered to address common challenges in plastic fastening. The zinc-plated steel construction offers a durable, corrosion-resistant base, while the Torx Plus IP6 drive system delivers exceptional torque transfer, minimizing tool slippage and head stripping. The core engineering value lies in the tri-lobe shank and thread forming (TRS) design, which displaces plastic material to form strong, load-bearing internal threads without cutting. This process significantly reduces hoop stress and the likelihood of plastic cracking, a critical failure point in assemblies. The fully threaded blunt tip and specific 0.79 mm thread pitch ensure easy starting and a consistent, reliable hold in thermoplastics and other polymer-based substrates, making them an optimal choice for electronics enclosures, automotive trim, and consumer goods.

Specification Summary & Compliance

This metric fastener features an M1.91 screw size with a 4 mm length and an approximate thread pitch of 0.79 mm. It is fully threaded and designed as a thread forming tapping screw (Type TRS) with a standard pan head and a right-hand thread direction. The product is manufactured to be RoHS 3 (2015/863/EU) Compliant and REACH (EC 1907/2006) Compliant, adhering to strict environmental and safety standards for industrial use.