S-91771A081 2-56 x 1/2" ASME B18.6.3 Stainless Steel Phillips Flat Head Screws

Key Features & Benefits at a Glance

• Superior corrosion resistance with passivated 18-8 stainless steel construction, ideal for harsh industrial environments and washdown applications
• Exceptional mechanical strength delivering 80,000 psi tensile strength and Rockwell B80 hardness for reliable performance under high stress
• Precision thread engagement with Class 2A UNC coarse threads providing secure fastening and reduced cross-threading risk
• Optimized flush mounting featuring standard 82° countersink angle for seamless surface integration and improved aesthetics
• Enhanced drive stability with Phillips No. 1 drive design ensuring consistent torque transmission and reduced cam-out
• Full regulatory compliance meeting ASME B18.6.3 specifications and environmental standards including RoHS 3 and REACH
• Complete thread coverage with fully threaded 1/2" length for maximum grip range and versatile application compatibility

Professional Applications & Engineering Value

These 2-56 UNC flat head screws deliver critical engineering advantages in demanding applications where surface flushness and corrosion resistance are paramount. The passivated 18-8 stainless steel construction provides exceptional protection against chemical exposure and oxidation, making them ideal for industrial equipment, electronic enclosures, and marine components. The UNC coarse thread design ensures rapid installation and superior holding power in various materials, while the standard 82° countersink angle guarantees proper seating in precision-machined components. With Phillips No. 1 drive compatibility, these screws offer familiar installation while maintaining the high tensile strength required for vibration-resistant assemblies in manufacturing, aerospace, and automotive applications.

Specification Summary & Compliance

Manufactured to exacting dimensional standards with Class 2A thread fit tolerance for consistent performance. Complies with ASME B18.6.3 mechanical and dimensional specifications, ensuring interchangeability and reliability. Meets RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) environmental compliance requirements. Features right-hand UNC coarse threads with complete threading along the 1/2" length, standard flat head profile, and proper drive engagement specifications for professional-grade fastening solutions.