S-98164A522 1/4"-28 x 3/4" ASME B18.3, ASTM F879 Stainless Steel Button Head Hex-Drive Screws

Key Features & Benefits at a Glance

• Superior corrosion resistance in harsh environments due to 316 stainless steel construction with passivated finish
• Exceptional thread engagement and vibration resistance achieved through Class 3A precision fit and UNF fine threading
• High mechanical strength with 70,000 psi tensile strength and Rockwell B55 hardness for demanding applications
• Secure installation and removal enabled by hex drive (5/32") and rounded button head design
• Full thread coverage along the 3/4" length provides maximum fastening contact and load distribution
• Regulatory compliance assurance meeting ASME B18.3 standards and environmental regulations (RoHS 3/REACH)
• Reliable performance consistency through standardized manufacturing specifications and quality control

Professional Applications & Engineering Value

This 316 stainless steel rounded head screw delivers critical performance advantages in corrosive and high-stress environments. The combination of UNF fine threading with Class 3A fit ensures precise engagement and superior vibration resistance, making it ideal for machinery, marine equipment, and chemical processing applications where loosening under dynamic loads is a concern. The passivated finish enhances the natural corrosion resistance of 316 stainless steel, providing extended service life in humid, saline, or chemically aggressive settings. With 70,000 psi tensile strength and full threading along its 3/4" length, this hex drive screw offers reliable fastening in structural assemblies, precision equipment, and industrial machinery where both strength and corrosion protection are paramount.

Specification Summary & Compliance

This rounded head screw maintains Class 3A thread fit precision according to UNF standards, ensuring tight tolerances and reliable performance. Manufacturing complies with ASME B18.3 specifications where applicable (ASTM F879), guaranteeing consistent quality and dimensional accuracy. The product is fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, meeting current environmental and safety standards for industrial components.