S-91257A163 1/2"-13 x 10 1/2" ASME B18.2.1, SAE J429 High-Strength Grade 8 Steel Hex Head Screws

Key Features & Benefits at a Glance

• Exceptional tensile strength with 150,000 psi rating ensures reliable performance under extreme loads, reducing failure risks in critical applications.
• Superior corrosion resistance from zinc yellow-chromate plating extends service life in harsh industrial environments, minimizing maintenance needs.
• High hardness level (Rockwell C33) provides excellent wear resistance, maintaining structural integrity through repeated use.
• Optimized thread design with UNC coarse threads and Class 2A fit enables faster installation and secure fastening in various materials.
• Partially threaded configuration allows for precise clamping force distribution, preventing joint loosening in vibration-prone applications.
• Standard-compliant manufacturing meeting ASME B18.2.1 and SAE J429 ensures consistent quality and interchangeability across industrial systems.
• External hex drive design with 3/4" head width offers superior torque transmission for efficient installation and removal with common tools.

Professional Applications & Engineering Value

Engineered for demanding industrial applications, these Grade 8 hex head screws deliver exceptional performance in construction machinery, heavy equipment assembly, and structural frameworks. The zinc yellow-chromate plated steel construction provides a robust barrier against corrosion, significantly extending service life in outdoor or chemically aggressive environments. The 1/2"-13 UNC coarse thread configuration ensures rapid installation and superior holding power in both soft and hard materials, while the partially threaded design concentrates clamping force precisely where needed, preventing stress concentration and joint failure. These high tensile strength bolts are particularly valuable in applications subject to vibration and dynamic loading, where their Rockwell C33 hardness maintains thread integrity through repeated torque cycles. The external hex drive compatibility with standard tools simplifies maintenance procedures, reducing downtime in industrial operations.

Specification Summary & Compliance

This hex head screw features precise Class 2A thread fit tolerances ensuring consistent engagement and reliable performance. Manufacturing complies with ASME B18.2.1 and SAE J429 specifications, guaranteeing dimensional accuracy and mechanical properties. The fastener maintains UNC coarse thread standards with 1/2"-13 threading and partial threading configuration. Material composition and zinc yellow-chromate plating meet industry standards for corrosion protection and environmental compliance.