S-91500A340 1/4"-20 x 2 1/4" ASME B18.6.3 Stainless Steel Phillips Flat Head Screws

Key Features & Benefits at a Glance

• Superior corrosion resistance with 316 stainless steel construction, ideal for harsh chemical and marine environments
• Enhanced durability and longevity thanks to passivated surface treatment that increases protection against oxidation
• Reliable high-strength performance with 70,000 psi tensile strength and Rockwell B80 hardness for demanding applications
• Precise, secure fastening ensured by Class 2A thread fit and UNC coarse threading for reduced cross-threading risk
• Efficient installation with Phillips No. 3 drive and standard flat head design for flush mounting
• Full-length thread engagement provides consistent clamping force along the entire 2-1/4" length
• Compliance with industry standards including ASME B18.6.3 for dimensional accuracy and quality assurance

Professional Applications & Engineering Value

This 316 stainless steel flat head screw delivers exceptional performance in corrosive environments where ordinary fasteners fail. The combination of marine-grade 316 stainless steel and passivated finish creates a robust barrier against saltwater, chemicals, and industrial atmospheres, significantly extending service life in marine equipment, chemical processing plants, and food processing machinery. The fully threaded UNC coarse thread design ensures maximum thread engagement and vibration resistance, while the 82° countersink angle provides a clean, flush finish that eliminates snagging hazards. With its Phillips drive and standardized flat head profile, installation efficiency is maximized in assembly line operations and maintenance applications where reliability and corrosion resistance are critical engineering requirements.

Specification Summary & Compliance

This fastener maintains Class 2A thread fit tolerance per ASME B18.6.3 specifications, ensuring precise dimensional accuracy and interchangeability. The 1/4"-20 UNC coarse thread configuration provides optimal performance in most industrial applications. Manufacturing complies with ASME B18.6.3 standards for dimensional consistency and quality. Environmental compliance includes RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) requirements, confirming the absence of restricted hazardous substances for global industrial use.