S-91375A638 3/8"-16 x 4" ASME B18.3, ASTM F912 Set Screws

Key Features & Benefits at a Glance

• Superior corrosion resistance with Black-Oxide finish, ideal for harsh industrial environments and extending service life.
• Exceptional holding power provided by the Class 3A thread fit, ensuring tight, secure, and vibration-resistant connections.
• High-strength durability from Alloy Steel and a Rockwell C45 hardness, capable of withstanding heavy-duty mechanical stress.
• Efficient installation and removal with the internal 3/16" Hex Drive and headless design, perfect for confined spaces.
• Reliable, non-slip grip thanks to the Cup Tip, which bites into the shaft to prevent component movement.
• Broad compatibility with UNC coarse threading (3/8"-16), making it a versatile choice for standard industrial assemblies.
• Guaranteed quality and safety by meeting ASME B18.3, RoHS 3, and REACH standards for regulated applications.

Professional Applications & Engineering Value

This Black-Oxide Alloy Steel set screw is engineered to solve critical challenges in power transmission and precision machinery. Its headless design and Hex Drive allow for flush mounting in tight spaces, preventing interference while enabling high torque application. The UNC coarse thread and Class 3A fit ensure rapid assembly with minimal cross-threading risk, maintaining alignment in pulleys, gears, and collars. The cup tip provides a concentrated point of contact, digging into shafts to resist loosening under high vibration—common in motors, conveyor systems, and automotive components. Combined with the Rockwell C45 hardness and protective oxide coating, it delivers long-term reliability in demanding industrial set screw applications, reducing maintenance and downtime.

Specification Summary & Compliance

This set screw adheres to precise dimensional standards, including a Class 3A thread fit for superior tolerance and a UNC 3/8"-16 coarse thread. It is manufactured in compliance with the ASME B18.3 specification, ensuring consistent quality and performance. The product is also verified to be RoHS 3 (2015/863/EU) Compliant and REACH (EC 1907/2006) Compliant, confirming its safety for use in regulated environments and commitment to environmental standards.