S-91385A918 1/2"-13 x 2" ASME B18.3, ASTM F912 Set Screws

Key Features & Benefits at a Glance

• Secure Vibration-Resistant Locking – Integrated nylon pellet thread locker prevents loosening under dynamic loads, maintaining clamp force in high-vibration environments
• Superior Corrosion Protection – Black-oxide coating on alloy steel provides enhanced rust resistance for extended service life in industrial conditions
• Precision Thread Engagement – Class 3A thread fit ensures tighter tolerances for more reliable fastening and reduced risk of cross-threading
• High-Temperature Compatibility – Thread locker maintains effectiveness up to 250°F (121°C), suitable for applications with elevated operating temperatures
• Optimized Drive Performance – 1/4" hex drive delivers maximum torque transmission while the headless design allows for flush mounting in confined spaces
• Exceptional Mechanical Strength – Rockwell C28 hardness provides durable wear resistance and deformation protection under heavy clamping loads
• Industry-Standard Compatibility – 1/2"-13 UNC coarse thread spacing ensures broad interchangeability with existing equipment and components

Professional Applications & Engineering Value

This black-oxide alloy steel set screw addresses critical challenges in industrial assembly where vibration-induced loosening and component slippage compromise system integrity. The nylon pellet thread locking mechanism creates consistent friction along the UNC coarse threads, effectively damping harmonic vibrations in machinery, power transmission systems, and rotating equipment. The headless design with hex drive enables precise depth adjustment while maintaining a zero-clearance profile for pulleys, collars, and coupling applications. Engineered to Class 3A thread fit standards, this fastener eliminates play in precision assemblies while the Rockwell C28 hardness ensures the cup point maintains gripping force without deforming under cyclical loading. Ideal for securing gears, bearings, and handles where temperature fluctuations up to 250°F are present.

Specification Summary & Compliance

Manufactured to ASME B18.3 specifications with Class 3A thread fit tolerances for precision engagement. Features 1/2"-13 UNC coarse thread configuration with right-hand direction and cup point design. Compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) environmental regulations. The black-oxide alloy steel construction meets ASTM F912 requirements for material composition and performance standards.