S-90403A081 2-56 x 3/8" ASME B18.13 Steel Pan Head Phillips Screws with Internal-Tooth Lock Washer

Key Features & Benefits at a Glance

• Superior corrosion resistance with zinc-plated steel construction, ensuring long-term durability in harsh industrial environments
• Reliable vibration resistance thanks to the integrated internal-tooth lock washer that prevents loosening under dynamic loads
• High tensile strength of 60,000 psi provides exceptional load-bearing capacity for demanding applications
• Easy installation and removal with Phillips No. 1 drive design, reducing assembly time and tool wear
• Precise Class 2A thread fit ensures smooth engagement and consistent clamping force in UNC coarse threads
• Full threading along the 3/8" length offers maximum grip and adjustment flexibility in various material thicknesses
• Comprehensive regulatory compliance meets ASME B18.13, RoHS 3, and REACH standards for global industrial use

Professional Applications & Engineering Value

Engineered for industrial assembly where vibration resistance and corrosion protection are critical, these zinc-plated steel screws with internal-tooth lock washers solve common fastening failures in machinery, electronics, and automotive components. The rounded pan head design distributes clamping force evenly, while the 2-56 UNC coarse thread and Class 2A fit provide rapid installation in metals and plastics without cross-threading. The combination of 60,000 psi tensile strength and Rockwell B69 hardness ensures reliable performance under cyclic loading, making these Phillips drive screws ideal for maintenance-free operations in heavy-duty fastening applications.

Specification Summary & Compliance

This fully threaded screw features precise Class 2A thread fit with UNC coarse threads (2-56 size) and complies with ASME B18.13 manufacturing specifications. The product is fully RoHS 3 (2015/863/EU) Compliant and REACH (EC 1907/2006) Compliant, ensuring adherence to international environmental and safety standards for industrial components.