S-91375A165 3-56 x 1/4" ASME B18.3, ASTM F912 Set Screws

Key Features & Benefits at a Glance

• Maximum holding power with Class 3A thread fit for secure, vibration-resistant fastening in precision assemblies
• Superior corrosion resistance from black-oxide alloy steel construction, extending service life in harsh industrial environments
• Enhanced durability with Rockwell C45 hardness, maintaining structural integrity under high-stress applications
• Precise component positioning using the cup point design that bites into surfaces without causing material damage
• Space-saving installation with headless design, ideal for confined spaces and flush-mount requirements
• Secure torque transmission through 0.050" hex drive, preventing tool slippage during installation
• Reliable fine thread engagement with 3-56 UNF right-hand threads for superior clamping force in thin materials

Professional Applications & Engineering Value

This 3-56 UNF set screw delivers critical engineering solutions for precision manufacturing and maintenance applications. The black-oxide alloy steel construction provides exceptional corrosion resistance while the Rockwell C45 hardness ensures the screw maintains its structural integrity under continuous vibration and load. The cup point design creates positive locking action by biting into shaft materials without causing excessive damage, making it ideal for permanent positioning of gears, pulleys, and collars on precision shafts. The headless configuration with hex drive allows for flush installation in space-constrained assemblies while providing reliable torque transmission. These set screws are particularly valuable in machinery, automotive, and aerospace applications where fine thread engagement and maximum holding power are required in thin-section components.

Specification Summary & Compliance

This precision fastener features 3-56 UNF right-hand threads with Class 3A thread fit for superior dimensional accuracy and tight tolerances. Manufactured to meet ASME B18.3 specifications (ASTM F912) ensuring consistent quality and performance. The product is fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) environmental regulations, making it suitable for global industrial applications with strict material restrictions.