S-91385A927 5/8"-11 x 1" ASME B18.3, ASTM F912 Set Screws

Key Features & Benefits at a Glance

• Secure Vibration Resistance – Built-in nylon pellet thread locker prevents loosening under dynamic loads, maintaining clamp force in high-vibration environments up to 250°F.
• Superior Corrosion Protection – Black-oxide finish on alloy steel provides enhanced rust resistance, extending service life in demanding industrial conditions.
• Precision Thread Engagement – UNC coarse threads with Class 3A fit ensure fast, accurate installation and reliable holding power in coarse-alignment applications.
• High-Strength Durability – Rockwell C28 hardness and alloy steel construction deliver excellent shear and tensile strength for heavy-duty mechanical assemblies.
• Tool-Friendly Installation – 5/16" hex drive allows high torque application with standard tools, while the headless design saves space in compact assemblies.
• Wide Thermal Compatibility – Nylon locking element functions effectively across a broad temperature range, suitable for various operating environments.
• Regulatory Peace of Mind – Complies with ASME B18.3, ASTM F912, RoHS 3, and REACH, ensuring material safety and standardized performance.

Professional Applications & Engineering Value

This Black-Oxide Alloy Steel set screw solves critical challenges in power transmission, machinery, and automotive systems where vibration-induced loosening compromises assembly integrity. The UNC coarse threading enables rapid installation in soft materials or castings, while the Class 3A thread fit guarantees precise engagement without cross-threading risks. The nylon pellet thread locker embedded in the 5/8"-11 threads creates consistent friction to resist back-out, eliminating the need for separate locking washers or adhesives. Combined with the cup tip design for positive seating on shafts and collars, this headless set screw delivers reliable positioning in pulleys, gears, and couplings—even in high-temperature environments up to 250°F. Its Rockwell C28 hardness ensures deformation resistance under heavy clamp loads, making it ideal for permanent or semi-permanent industrial fastening applications.

Specification Summary & Compliance

This set screw features 5/8"-11 UNC coarse threads with Class 3A tolerance for superior fit and consistent performance. Manufactured to ASME B18.3 and ASTM F912 specifications, it guarantees dimensional accuracy and mechanical properties. The product is fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, ensuring environmental safety and restricted substance adherence for global industrial use.