S-91771A973 1/4"-20 x 1" 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
• High tensile strength of 80,000 psi ensures reliable performance under significant mechanical stress
• Rockwell B80 hardness provides excellent durability and resistance to wear over extended use
• 100° countersink angle and flat head design allows for flush mounting, creating smooth, snag-free surfaces
• Fully threaded UNC coarse thread delivers faster installation and superior holding power in various materials
• Class 2A thread fit guarantees consistent, precise engagement for reliable assembly
• Phillips No. 3 drive enables efficient torque application with standard tools, reducing installation time

Professional Applications & Engineering Value

These 1/4"-20 UNC flat head Phillips screws are engineered to solve critical challenges in industrial assembly and machinery. The passivated 18-8 stainless steel provides exceptional resistance to rust and chemical exposure, making them perfect for outdoor equipment, marine applications, and food processing machinery where moisture is a concern. The fully threaded coarse UNC thread ensures rapid installation and strong retention in metals, plastics, and wood, while the 100° countersink angle creates a seamless finish that prevents interference in moving parts. With their 80,000 psi tensile strength, they maintain structural integrity in high-vibration environments, reducing maintenance needs and downtime in automotive, aerospace, and construction applications.

Specification Summary & Compliance

This screw meets ASME B18.6.3 specifications for dimensional accuracy and performance. Threads conform to UNC coarse thread standards with Class 2A fit, ensuring precise tolerances for reliable fastening. The product is fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, confirming it is free from hazardous substances and safe for various industrial and commercial applications worldwide.