S-91677A110 1/4"-20 x 3/4" Set Screws

Key Features & Benefits at a Glance

• Enhanced Tip Durability – The Rockwell C60 hardened alloy steel ball tip resists wear and deformation, ensuring reliable, long-term holding power in high-stress applications.
• Superior Corrosion Resistance – The black-oxide finish on the alloy steel body provides a protective layer, increasing the screw's lifespan in various industrial environments.
• Precise Thread Engagement – Class 2A thread fit with UNC coarse threads offers consistent, secure fastening with reduced risk of cross-threading during installation.
• High Torque Application – The 1/8" hex drive allows for high torque transfer with standard tools, enabling secure installation in headless designs where space is limited.
• Optimized for Vibration Resistance – The coarse 1/4"-20 thread and ball tip design help maintain clamp load and resist loosening under dynamic or vibrating conditions.
• Broad Material Compatibility – The alloy steel construction with controlled hardness (Rockwell C32 body, C60 tip) provides an excellent balance of strength and toughness for mating with various materials.
• Regulatory Compliance Assurance – Meets RoHS 3 and REACH standards, ensuring the screw is safe for use in regulated markets and environmentally conscious supply chains.

Professional Applications & Engineering Value

This black-oxide alloy steel set screw is engineered to address critical challenges in industrial assembly and precision machinery. The headless design with a 1/8" hex drive is ideal for applications where protruding fasteners are not feasible, such as in shaft collars, gears, and pulleys. The Rockwell C60 ball tip bites securely into the contact surface, preventing slippage and distributing force evenly to minimize damage to the shaft or component. Combined with UNC coarse threads and a Class 2A thread fit, this screw ensures rapid installation and reliable performance in high-vibration environments, reducing maintenance needs and downtime. Its right-hand thread direction and robust alloy steel construction make it a dependable choice for OEMs and MRO professionals seeking durability and compliance.

Specification Summary & Compliance

This set screw adheres to UNC thread standards with a 1/4"-20 coarse thread and Class 2A thread fit, ensuring dimensional accuracy and interchangeability. The manufacturing process follows industry norms for alloy steel fasteners, with a body hardness of Rockwell C32 and a tip hardness of Rockwell C60. It is fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, confirming its suitability for use in products requiring strict environmental and safety standards.