S-91251A956 1 1/2"-6 x 4" 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 industrial applications
• Superior corrosion resistance with black-oxide coating protects against rust and extends service life
• Precision Class 2A thread fit guarantees consistent engagement and reduces assembly issues
• Heavy-duty alloy steel construction with Rockwell C37 hardness provides excellent durability and wear resistance
• Standard hex drive design with 1" drive size enables secure installation and removal with common tools
• Fully threaded configuration offers maximum grip length and versatile fastening capabilities
• Comprehensive compliance with ASTM A574, RoHS 3, and REACH ensures quality and environmental safety

Professional Applications & Engineering Value

These black-oxide alloy steel socket head cap screws deliver critical performance in demanding industrial environments where failure is not an option. The combination of 170,000 psi tensile strength and Rockwell C37 hardness provides exceptional resistance to vibration loosening and structural fatigue. The UNRC coarse threads with Class 2A fit ensure rapid assembly without cross-threading risks, while the fully threaded design maximizes clamping force distribution. Ideal for heavy machinery, structural steel connections, and high-vibration equipment, these socket head cap screws maintain integrity under extreme loads. The black-oxide surface treatment offers additional corrosion protection in harsh operating conditions, making them suitable for outdoor industrial applications and manufacturing equipment where reliability is paramount.

Specification Summary & Compliance

Manufactured to ASTM A574 specifications with Class 2A thread fit and UNRC coarse threads (1 1/2"-6). Features include right-hand thread direction, standard socket head profile, and inch system measurements. Full compliance with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) environmental regulations. Dimensions include 4" length, 2 1/4" head diameter, and 1 1/2" head height with 1" hex drive size.