S-97705A246 4-40 x 1/2" QQ-P-35, MS51021-15 Set Screws

Key Features & Benefits at a Glance

• Superior corrosion resistance with 18-8 stainless steel construction, ideal for harsh environments and long-term reliability.
• Exceptional holding power from the cup point design, which bites into shafts and components to prevent loosening under vibration.
• High-precision Class 3A thread fit ensures tight, secure fastening with minimal backlash in demanding applications.
• Easy installation and removal with the internal hex drive (0.050"), allowing efficient assembly even in confined spaces due to the headless design.
• Robust UNC coarse threading provides quick assembly and reduced cross-threading risk compared to fine threads.
• Compliance with stringent standards including Fed. Spec. QQ-P-35 (MS51021-15), ensuring consistent quality and performance.
• Environmentally safe operation with full RoHS 3 and REACH compliance, meeting global regulatory requirements for hazardous substances.

Professional Applications & Engineering Value

This 4-40 UNC set screw is engineered to address critical challenges in precision assemblies, such as securing collars, gears, and pulleys on shafts without protruding heads. The 18-8 stainless steel material offers excellent resistance to rust and oxidation, making it suitable for applications in machinery, automotive, and electronics exposed to moisture or chemicals. The headless hex drive design allows for flush mounting in tight spaces, while the cup point creates a firm grip that resists rotational forces and vibration-induced loosening. With its coarse thread spacing and Class 3A thread fit, it ensures rapid installation and reliable performance in high-stress environments, reducing maintenance needs and enhancing operational efficiency.

Specification Summary & Compliance

This set screw adheres to precise dimensional standards, including a Class 3A thread fit for tight tolerances and UNC coarse threading (4-40 size) with a thread diameter of 0.112". It meets Fed. Spec. QQ-P-35 (MS51021-15) for material and manufacturing consistency, and is fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, ensuring safety and environmental responsibility.