S-91247A036 1/4"-28 x 6 1/2" ASME B18.2.1, SAE J429 Medium-Strength Grade 5 Steel Hex Head Screws

Key Features & Benefits at a Glance

• Exceptional load-bearing capacity with Grade 5 classification and 120,000 psi tensile strength for reliable performance in demanding applications
• Superior corrosion resistance through zinc plating, extending service life in harsh industrial environments
• Optimized thread engagement with UNF fine threading and Class 2A fit ensuring vibration resistance and secure fastening
• Enhanced installation efficiency featuring external hex drive and 7/16" head width for easy tool access and high torque application
• Controlled clamping force distribution through partial threading design preventing joint loosening under dynamic loads
• Consistent mechanical properties with Rockwell C25 hardness maintaining dimensional stability under stress
• Reduced maintenance requirements with compliant coatings and materials meeting RoHS 3 and REACH environmental standards

Professional Applications & Engineering Value

Engineered for heavy-duty industrial applications, these Grade 5 hex head screws solve critical fastening challenges in machinery assembly, structural frameworks, and equipment manufacturing. The partially threaded 1/4"-28 UNF design provides optimal stress distribution while the zinc plated steel construction delivers reliable corrosion protection in demanding environments. With external hex drive compatibility and fine thread spacing, installers achieve precise torque control and vibration-resistant connections. The 6 1/2" length accommodates thick material sections while maintaining Class 2A thread fit accuracy, ensuring consistent performance in automotive, construction, and industrial maintenance applications where joint integrity is paramount.

Specification Summary & Compliance

Manufactured to ASME B18.2.1 and SAE J429 specifications with Class 2A thread fit tolerances. Compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) environmental regulations. Features 1/4"-28 UNF fine threads with minimum 1" thread length on a 6 1/2" overall length. Mechanical properties include 120,000 psi tensile strength and Rockwell C25 hardness consistent with Grade 5 requirements.