S-91249A371 1/4"-28 x 3/4" ASME B18.6.3 Stainless Steel Pan Head Phillips Screws

Key Features & Benefits at a Glance

• Superior corrosion resistance with black-oxide coating over 18-8 stainless steel, ideal for harsh industrial environments
• Exceptional mechanical strength with 70,000 psi tensile strength and Rockwell B70 hardness for reliable load-bearing performance
• Precision thread engagement with Class 2A UNF fine threads ensuring secure, vibration-resistant fastening
• Optimized drive efficiency through No. 3 Phillips drive and rounded pan head design for easier installation and reduced cam-out
• Full-threaded construction providing maximum grip length and uniform stress distribution along the entire fastener
• Regulatory compliance assurance meeting ASME B18.6.3 manufacturing standards and environmental regulations (RoHS 3 & REACH)
• Versatile size compatibility with 1/4"-28 UNF thread and 3/4" length fitting standard industrial applications

Professional Applications & Engineering Value

Engineered for demanding industrial applications, these black-oxide 18-8 stainless steel screws combine material excellence with precision manufacturing. The UNF fine thread configuration delivers superior vibration resistance in machinery, automotive assemblies, and electrical enclosures where loosening under dynamic loads is a critical concern. The fully threaded design ensures maximum thread engagement in both thick and thin materials, while the rounded pan head with Phillips drive provides flush mounting and efficient installation with standard tools. This combination addresses common engineering challenges including corrosion in humid environments, the need for high tensile strength in structural applications, and requirements for consistent thread fit in precision assemblies.

Specification Summary & Compliance

This rounded head screw features precision 1/4"-28 UNF fine threads with Class 2A thread fit per ASME standards, ensuring consistent dimensional accuracy and proper engagement. Manufacturing complies with ASME B18.6.3 specifications for dimensional requirements and quality standards. The product is RoHS 3 (2015/863/EU) Compliant and REACH (EC 1907/2006) Compliant, meeting current environmental regulations for hazardous substance restrictions. The 18-8 stainless steel construction with black-oxide surface treatment provides both mechanical reliability and corrosion protection for long-term performance.