S-90289A561 1/4"-28 x 3/4" ASME B18.3 Set Screws

Key Features & Benefits at a Glance

• Superior corrosion resistance with black-oxide alloy steel coating, extending service life in harsh industrial environments.
• Precise Class 3A thread fit ensures tight, reliable fastening with minimal backlash for vibration-prone applications.
• High Rockwell C45 hardness provides excellent wear resistance and durability under heavy mechanical loads.
• Hex drive design allows for secure, high-torque installation and removal with standard tools, reducing assembly time.
• Cup tip configuration delivers concentrated clamping force, preventing component slippage in machinery assemblies.
• Compliance with ASME B18.3 standards guarantees consistent quality and interchangeability for engineering projects.
• RoHS 3 and REACH compliance ensures environmental safety and regulatory adherence for global supply chains.

Professional Applications & Engineering Value

Engineered for demanding industrial settings, this black-oxide alloy steel set screw combines high hardness (Rockwell C45) with a fine UNF thread to address common challenges like vibration loosening and material fatigue. The headless design with hex drive facilitates flush mounting in confined spaces, while the cup tip ensures firm grip on shafts and collars in machinery, automotive, and precision equipment. Its Class 3A thread fit and right-hand threading provide reliable, repeatable fastening, reducing maintenance downtime and enhancing operational safety in heavy-duty fastener applications.

Specification Summary & Compliance

This set screw adheres to ASME B18.3 specifications, with precise 1/4"-28 UNF fine threads and Class 3A thread fit for tight tolerances. It meets RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) compliance, ensuring no hazardous substances are used. Dimensions include a 3/4" length, 1/8" hex drive, and 0.25" thread diameter, manufactured from alloy steel with serrations for enhanced locking performance.