S-94063A552 1/4"-20 x 2 1/2" ASME B18.6.3 Tamper-Resistant Drilled Spanner Flat Head Screws

Key Features & Benefits at a Glance

• Superior corrosion resistance with 18-8 Stainless Steel and passivated finish for long-lasting performance in harsh environments.
• High tensile strength of 70,000 psi and Rockwell B70 hardness ensure reliable load-bearing capacity and durability in demanding applications.
• Precise Class 2A thread fit guarantees smooth installation and secure fastening, reducing assembly time and improving joint integrity.
• Standard 82° countersink angle and flat head design provide a flush, unobtrusive finish for streamlined surfaces and enhanced safety.
• Drilled spanner drive (No. 14 size) offers secure tool engagement, minimizing slippage and damage during installation or removal.
• Partially threaded shank allows for controlled clamping force, ideal for materials requiring specific grip ranges without over-tightening.
• Compliance with ASME B18.6.3, RoHS 3, and REACH ensures adherence to industry standards and environmental regulations for global supply chain compatibility.

Professional Applications & Engineering Value

This 1/4"-20 UNC flat head screw is engineered to address critical industrial challenges, such as vibration loosening and corrosion-induced failure. The 18-8 Stainless Steel material, combined with a passivated finish, provides exceptional resistance to rust and chemicals, making it suitable for outdoor, marine, and chemical processing equipment. The partially threaded design and Class 2A thread fit ensure precise engagement in metals and composites, reducing stress concentration and improving fatigue life. Commonly used in machinery, automotive assemblies, and structural frameworks, these screws deliver reliable performance where flush mounting and high strength are paramount, supported by the drilled spanner drive for secure torque application in confined spaces.

Specification Summary & Compliance

This screw features a 1/4"-20 UNC coarse thread with Class 2A fit for consistent dimensional accuracy, a minimum thread length of 1-1/2", and overall length of 2-1/2". It meets ASME B18.6.3 specifications for dimensional and mechanical properties, and is fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, ensuring environmental safety and material restrictions adherence.