S-98164A523 1/4"-28 x 1" ASME B18.3, ASTM F879 Stainless Steel Button Head Hex-Drive Screws

Key Features & Benefits at a Glance

• Superior corrosion resistance with 316 stainless steel construction and passivated finish, ideal for harsh chemical and marine environments
• Exceptional thread precision with Class 3A fit ensuring reliable, vibration-resistant connections in critical assemblies
• High tensile strength of 70,000 psi provides durable fastening performance under heavy mechanical loads
• Consistent Rockwell B55 hardness maintains structural integrity and prevents thread deformation during installation
• Optimized hex drive engagement with 5/32" drive size prevents cam-out and enables efficient torque transmission
• Full threading design allows maximum grip length and uniform stress distribution across the entire fastener
• Regulatory compliance assurance with ASME B18.3 standards and RoHS 3/REACH certifications for global market acceptance

Professional Applications & Engineering Value

This 1/4"-28 UNF rounded head hex screw delivers critical performance advantages in demanding industrial applications where corrosion resistance and thread precision are paramount. The 316 stainless steel composition combined with passivated surface treatment provides exceptional protection against chloride-induced stress corrosion cracking, making it ideal for chemical processing equipment, marine hardware, and food processing machinery. The Class 3A thread fit ensures minimal clearance between mating components, eliminating vibration-induced loosening in precision assemblies. The button head profile with hex drive offers both aesthetic appeal and practical installation benefits, creating low-profile connections while the fine UNF threading provides superior resistance to vibrational forces compared to coarse thread alternatives.

Specification Summary & Compliance

This precision fastener features Class 3A thread tolerances per UNF standards with 1/4"-28 fine threading and right-hand thread direction. Manufacturing complies with ASME B18.3 specifications (ASTM F879) ensuring dimensional accuracy and performance reliability. The screw meets stringent environmental regulations including RoHS 3 (2015/863/EU) compliance and REACH (EC 1907/2006) certification, confirming absence of restricted substances. Mechanical properties include 70,000 psi tensile strength and Rockwell B55 hardness for consistent performance in industrial fastening applications.