S-91251A195 2-56 x 1 1/4" ASTM A574 Alloy Steel Socket Head Screws

Key Features & Benefits at a Glance

• Superior corrosion resistance with black-oxide coating, extending service life in demanding industrial environments
• Exceptional mechanical strength with 170,000 psi tensile strength and Rockwell C37 hardness for heavy-duty applications
• Precision thread engagement with Class 3A fit ensuring reliable, vibration-resistant connections
• Optimized drive efficiency through hex socket design with 5/64" drive for secure tool engagement
• Versatile partial threading allowing both threaded engagement and smooth shank functionality
• Industry-standard compliance meeting ASTM A574 specifications for consistent quality assurance
• Environmental responsibility with RoHS 3 and REACH compliance for sustainable manufacturing

Professional Applications & Engineering Value

These black-oxide alloy steel socket head cap screws deliver critical performance advantages in precision assemblies where high tensile strength and corrosion resistance are paramount. The UNC coarse thread configuration with Class 3A fit provides superior vibration resistance in dynamic applications, while the partially threaded design offers flexibility for both clamping and alignment functions. The hex socket drive ensures maximum torque transmission without cam-out, making these industrial fasteners ideal for machinery, automotive components, and electronic enclosures requiring reliable, high-strength connections in confined spaces.

Specification Summary & Compliance

Manufactured to exacting ASTM A574 standards with Class 3A thread fit precision and UNC coarse thread spacing. These 1-1/4" length screws feature 5/64" hex drive compatibility and right-hand thread direction. Full compliance with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) environmental regulations ensures responsible manufacturing practices for global industrial applications.