S-91251A926 1"-8 x 5 1/2" ASTM A574 Alloy Steel Socket Head Screws

Key Features & Benefits at a Glance

• Exceptional tensile strength of 170,000 psi ensures reliable performance in high-stress applications, reducing the risk of fastener failure.
• Superior corrosion resistance from the black-oxide finish extends service life in harsh industrial environments, minimizing maintenance needs.
• Precise Class 3A thread fit provides tighter tolerances for secure, vibration-resistant assemblies, enhancing joint integrity.
• High hardness rating (Rockwell C37) offers excellent wear resistance, maintaining thread integrity through repeated use.
• Coarse 1"-8 UNRC threads enable faster installation and better performance in materials prone to stripping or galling.
• Partially threaded design allows for precise clamping force control where full threading isn't required.
• Industry compliance with ASTM A574, RoHS 3, and REACH ensures material quality and environmental responsibility.

Professional Applications & Engineering Value

Engineered for heavy-duty industrial applications, these black-oxide alloy steel socket head cap screws solve critical fastening challenges where vibration resistance and corrosion protection are paramount. The 1"-8 UNRC coarse thread configuration prevents cross-threading in high-production environments while the Class 3A thread fit maintains precise alignment in precision machinery. The partially threaded design provides optimal stress distribution in structural assemblies, while the 170,000 psi tensile strength ensures reliability in load-bearing applications from heavy equipment to construction machinery. The black-oxide surface treatment creates a protective barrier against moisture and chemicals, significantly extending service life in demanding conditions without compromising the alloy steel's inherent strength properties.

Specification Summary & Compliance

These socket head cap screws feature precision Class 3A thread fit with 1"-8 UNRC coarse threads and 2 1/2" minimum thread length. Manufactured to ASTM A574 specification for high-strength alloy steel fasteners, they maintain dimensional accuracy throughout production. Compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) environmental regulations, ensuring restricted substance compliance for global industrial applications.