S-90403A838 1/4"-20 x 1 1/2" ASME B18.13 Steel Pan Head Phillips Screws with Internal-Tooth Lock Washer

Key Features & Benefits at a Glance

• Superior Vibration Resistance: Integrated internal-tooth lock washer ensures secure fastening under dynamic loads, reducing maintenance needs.
• Enhanced Durability & Corrosion Protection: Zinc-plated steel construction offers excellent resistance to rust and wear in harsh industrial environments.
• High Tensile Strength for Demanding Applications: 60,000 psi tensile strength and Rockwell B69 hardness provide reliable performance under high stress.
• Effortless Installation & Removal: Phillips No. 3 drive and coarse UNC threads enable quick, straightforward assembly with standard tools.
• Precision Thread Fit for Secure Connections: Class 2A thread fit ensures consistent, reliable engagement without cross-threading risks.
• Versatile Fully Threaded Design: Maximizes grip along the entire 1-1/2" length for uniform clamping force in various materials.
• Regulatory Compliance for Global Use: Meets ASME B18.13 standards, RoHS 3, and REACH, ensuring safety and environmental adherence.

Professional Applications & Engineering Value

This zinc-plated steel pan head screw with an internal-tooth lock washer is engineered to address critical challenges in industrial assembly, such as vibration-induced loosening and corrosion. The coarse UNC 1/4"-20 thread and Class 2A fit provide rapid installation and reliable holding power in metal, wood, and composite materials, reducing assembly time and improving joint integrity. With a fully threaded design and 60,000 psi tensile strength, it distributes load evenly, preventing fatigue failures in machinery, automotive, and electrical enclosures. The Phillips drive ensures compatibility with common tools, while the zinc plating extends service life in humid or outdoor settings, making it ideal for vibration-resistant applications where safety and durability are paramount.

Specification Summary & Compliance

This screw features a 1/4"-20 UNC coarse thread with Class 2A tolerance for precise fit, and is fully threaded over a 1-1/2" length. It complies with ASME B18.13 manufacturing standards, ensuring dimensional accuracy and performance. Additionally, it is RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) compliant, meeting environmental and safety regulations for industrial use.