S-91253A542 1/4"-20 x 1" ASTM F835 Alloy Steel Hex Drive Flat Head Screws

Key Features & Benefits at a Glance

• Superior corrosion resistance with black-oxide coating, extending service life in harsh industrial environments
• Exceptional tensile strength of 130,000 psi ensures reliable performance under high-stress applications
• Precision Class 3A thread fit provides superior engagement and vibration resistance in critical assemblies
• Optimized hex drive design (5/32") enables secure tool engagement and reduces stripping during installation
• 82° countersink angle allows for flush mounting while maintaining structural integrity
• Full threading delivers maximum holding power across the entire fastener length
• Rockwell C39 hardness maintains dimensional stability and prevents deformation under load

Professional Applications & Engineering Value

These 1/4"-20 UNC flat head hex drive screws in black-oxide alloy steel address critical engineering challenges in industrial fastening. The combination of Class 3A thread fit and coarse threading ensures rapid installation while maintaining vibration resistance in machinery, automotive, and heavy equipment applications. The black-oxide surface treatment provides essential corrosion protection without compromising dimensional accuracy, making these fully threaded screws ideal for applications requiring both precision alignment and environmental durability. The 82° countersink angle and flat head profile facilitate seamless integration into assembled components while the hex drive design prevents cam-out during high-torque installation.

Specification Summary & Compliance

Manufactured to exacting Class 3A thread fit tolerances with UNC coarse threading (1/4"-20) and right-hand thread direction. Compliant with ASME B18.3 and ASTM F835 specifications for dimensional accuracy and performance. Meets environmental standards including RoHS 3 (2015/863/EU) compliance and REACH (EC 1907/2006) requirements for hazardous substances.