S-90778A105 4-40 x 3/16" ASME B18.3 Set Screws

Key Features & Benefits at a Glance

• Superior corrosion resistance with 316 Stainless Steel construction, ideal for harsh environments and extended service life
• Exceptional thread precision with Class 3A fit ensures reliable, vibration-resistant fastening and prevents loosening
• High-strength performance backed by Rockwell B80 hardness for durable, non-deforming connections under load
• Secure component positioning with a 90° cone point that bites into surfaces for positive location and anti-rotation
• Easy installation and removal using a standard 0.050" hex key, providing a flush, headless finish in assembled applications
• Broad industrial compatibility with coarse UNC 4-40 threads for quick assembly and robust holding power
• Regulatory peace of mind through compliance with RoHS 3 and REACH, meeting strict environmental and safety standards

Professional Applications & Engineering Value

This 4-40 UNC set screw is engineered to address critical challenges in precision assembly and machinery. The 316 Stainless Steel material offers outstanding resistance to chemicals, moisture, and high temperatures, making it suitable for demanding sectors like marine, chemical processing, and food equipment. The headless design and hex drive allow for a sleek, space-saving installation, while the cone point with a 90° angle ensures firm gripping on shafts, gears, and collars—preventing slippage and maintaining alignment. With a Class 3A thread fit and coarse thread spacing, it delivers quick, secure fastening that withstands vibrations and dynamic loads, reducing maintenance needs and enhancing operational reliability in industrial settings.

Specification Summary & Compliance

This set screw adheres to ASME B18.3 specifications, ensuring dimensional accuracy and interchangeability. Thread details include a 4-40 UNC size with Class 3A tolerance for precise, tight fits. The product is fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006), confirming it is free of hazardous substances and safe for various industrial applications.