S-91247A134 5/16"-24 x 5 1/2" ASME B18.2.1, SAE J429 Medium-Strength Grade 5 Steel Hex Head Screws

Key Features & Benefits at a Glance

• Enhanced load-bearing capability with 120,000 psi tensile strength and Grade 5 classification for reliable performance in demanding environments.
• Superior corrosion resistance from zinc plating, extending service life in industrial settings exposed to moisture and harsh conditions.
• Precise thread engagement with 5/16"-24 UNF fine threading and Class 2A fit, ensuring secure fastening and vibration resistance.
• Optimized torque application via external hex drive and standard 1/2" head width, facilitating easy installation with common tools.
• Durable material integrity from steel construction and Rockwell C25 hardness, providing consistent strength without brittleness.
• Versatile partial threading design allowing unthreaded shank sections for shear strength where full threading isn't required.
• Regulatory compliance assurance meeting ASME B18.2.1, SAE J429, RoHS 3, and REACH standards for quality and environmental safety.

Professional Applications & Engineering Value

This Grade 5 hex head screw delivers critical reliability in heavy-duty applications where joint integrity is paramount. The 5/16"-24 UNF fine thread configuration provides superior resistance to loosening under dynamic loads, while the zinc-plated steel construction combats corrosion in manufacturing, construction, and machinery assembly environments. The partially threaded design allows the unthreaded portion to bear against shear forces, making it ideal for pivoting mechanisms or structural connections requiring precise clamp load distribution. With external hex drive compatibility, installation torque is efficiently transferred without stripping, reducing assembly time and maintenance costs in industrial fastening systems.

Specification Summary & Compliance

Manufactured to ASME B18.2.1 and SAE J429 specifications, this screw maintains Class 2A thread fit tolerances for consistent engagement. The 5/16"-24 UNF fine thread with right-hand direction ensures compatibility with standard components, while the 5 1/2" length and 7/8" minimum thread length provide versatile fastening options. Full compliance with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations guarantees environmentally safe usage in global supply chains.