S-91205A072 2-56 x 1" ASME B18.3, ASTM A574 Alloy Steel Thread-Locking Socket Head Screws

Key Features & Benefits at a Glance

• Superior vibration resistance with permanent nylon patch thread locker that prevents loosening under dynamic loads
• Exceptional tensile strength of 170,000 psi ensures reliable performance in high-stress applications
• Precise Class 3A thread fit provides consistent engagement and reduces assembly issues
• Wide temperature tolerance from -70° to 250°F maintains locking performance in extreme environments
• Corrosion-resistant black-oxide finish on alloy steel extends service life in demanding conditions
• Standard hex drive compatibility with 5/64" tools enables quick installation and removal
• Partially threaded design offers flexibility for applications requiring precise clamping control

Professional Applications & Engineering Value

These black-oxide alloy steel socket head cap screws with 2-56 UNC coarse threads solve critical fastening challenges in industrial equipment, machinery, and precision assemblies. The combination of 170,000 psi tensile strength and Rockwell C37 hardness ensures dependable performance where vibration and heavy loads would compromise ordinary fasteners. The permanent nylon patch thread locker eliminates the need for secondary locking components, reducing assembly time while providing reliable vibration resistance from -70° to 250°F. The standard hex drive design allows for high torque application in confined spaces, making these screws ideal for automotive, aerospace, and manufacturing applications where space constraints and reliability are paramount.

Specification Summary & Compliance

Manufactured to ASME B18.3 specifications with Class 3A thread fit for superior dimensional accuracy. These socket head cap screws meet ASTM A574 material standards and feature UNC coarse thread spacing with right-hand thread direction. Fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) environmental regulations for safe industrial use worldwide.