S-91381A547 1/4"-20 x 1 1/4" ASME B18.3 Set Screws

Key Features & Benefits at a Glance

• Precise thread engagement with Class 3A fit ensures reliable, vibration-resistant fastening in demanding applications.
• Enhanced corrosion resistance from the black-oxide finish prolongs service life in harsh industrial environments.
• Secure, non-marring contact with the soft brass tip prevents damage to expensive shafts and components.
• High-strength performance from alloy steel with Rockwell C28 hardness provides excellent durability and load-bearing capacity.
• Easy installation and removal using the 1/8" hex drive, ideal for confined spaces due to the headless design.
• Wide compatibility with the 1/4"-20 UNC coarse thread, a standard in North American machinery and equipment.
• Regulatory peace of mind with compliance to ASME B18.3, RoHS 3, and REACH for safe, quality-assured use.

Professional Applications & Engineering Value

This black-oxide alloy steel set screw is engineered to address common industrial challenges like component slippage and surface damage. The headless design and hex drive allow for flush mounting in tight spaces, while the soft brass tip distributes pressure evenly to prevent gouging on precision shafts or gears. With a Class 3A thread fit and coarse UNC thread, it maintains a secure hold against vibrations in machinery, automotive assemblies, and power transmission systems. The Rockwell C28 hardness and corrosion-resistant coating ensure it withstands heavy loads and environmental exposure, reducing maintenance needs and downtime in industrial set screw applications.

Specification Summary & Compliance

This set screw features a 1/4"-20 UNC coarse thread with Class 3A precision tolerance for accurate fit. It adheres to the ASME B18.3 manufacturing standard and is compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, ensuring environmental safety and material quality.