S-95345A446 4-40 x 7/8" ASME B18.13 Stainless Steel Pan Head Phillips Screws with External-Tooth Lock Washer

Key Features & Benefits at a Glance

• Superior Vibration Resistance: Integrated external-tooth lock washer bites into surfaces to prevent loosening under dynamic loads, ensuring long-term assembly integrity.
• Exceptional Corrosion Resistance: Made from 18-8 stainless steel with a passivated finish, offering reliable performance in humid, chemical, or outdoor environments.
• High Tensile Strength: Withstands up to 70,000 psi, providing robust fastening for high-stress mechanical and industrial applications.
• Secure & Efficient Installation: No. 1 Phillips drive and rounded pan head design allow for easy torque application and reduced risk of cam-out during assembly.
• Wide Compatibility: Coarse UNC threads and Class 2A fit ensure easy engagement and reliable performance in a variety of materials and pre-tapped holes.
• Full-Length Threading: Enables maximum adjustability and holding power along the entire 7/8" length, suitable for varying material thicknesses.
• Regulatory Compliance: Meets ASME B18.13 specifications and environmental standards (RoHS 3, REACH), ensuring safety and suitability for regulated industries.

Professional Applications & Engineering Value

This 4-40 UNC coarse thread screw with an integrated external-tooth lock washer is engineered to solve critical fastening challenges in vibration-prone and corrosive environments. The 18-8 stainless steel construction, enhanced by a passivated finish, resists oxidation and chemical attack, making it ideal for electronics enclosures, machinery panels, automotive components, and outdoor equipment. The lock washer’s teeth dig into mating surfaces, eliminating the need for additional locking mechanisms and reducing maintenance costs. Fully threaded and with a rounded pan head for smooth profile and Phillips drive for controlled installation, it ensures reliable, repeatable performance in assembly lines and field service, minimizing downtime and replacement frequency.

Specification Summary & Compliance

This screw features a 4-40 UNC coarse thread with Class 2A fit for standard tolerance applications, ensuring consistent thread engagement. It is fully threaded and measures 7/8" in length, with a head diameter of 0.219". Manufacturing and quality adhere to ASME B18.13 specifications. The product is confirmed RoHS 3 (2015/863/EU) Compliant and REACH (EC 1907/2006) Compliant, meeting environmental and safety regulations for global industrial use.