S-91253A141 4-48 x 1/4" ASTM F835 Alloy Steel Hex Drive Flat Head Screws

Key Features & Benefits at a Glance

• Superior corrosion resistance with black-oxide coating that protects against rust and extends service life in demanding environments
• Exceptional tensile strength of 130,000 psi ensures reliable performance under high-stress industrial applications
• Precision Class 3A thread fit provides superior engagement and vibration resistance in critical assemblies
• Optimized flush mounting with 82° countersink angle and flat head design for seamless surface integration
• Enhanced torque transmission through hex drive design prevents stripping and enables secure installation
• Full threading capability along the entire 1/4" length ensures maximum holding power and adjustment flexibility
• Compliance assurance with ASTM F835, RoHS 3, and REACH standards for quality and environmental responsibility

Professional Applications & Engineering Value

These 4-48 UNF flat head screws deliver critical performance advantages for precision engineering applications where space constraints and reliability are paramount. The black-oxide alloy steel construction combined with Rockwell C39 hardness provides exceptional durability against wear and environmental exposure. The fine UNF threading with Class 3A fit ensures superior vibration resistance in machinery, electronic enclosures, and aerospace components where loosening could cause catastrophic failure. The 82° countersink angle allows for perfect flush mounting in precision instruments and manufactured assemblies, while the hex drive facilitates secure installation in confined spaces. These industrial fasteners solve critical challenges in applications requiring high-strength, corrosion-resistant fastening solutions with precise dimensional control.

Specification Summary & Compliance

Manufactured to exacting standards with Class 3A thread fit precision and UNF (Unified National Fine) thread specifications. These screws maintain dimensional accuracy with 1/4" length and 4-48 thread size for consistent performance. Compliance includes ASTM F835 manufacturing specifications, RoHS 3 (2015/863/EU) compliance for hazardous substance restriction, and REACH (EC 1907/2006) compliance for chemical safety. The right-hand threading direction and fully threaded design ensure reliable performance across industrial applications requiring high-strength fastening solutions.