S-92311A331 6-40 x 3/8" ASME B18.3 Set Screws

Key Features & Benefits at a Glance

• Exceptional corrosion resistance with 18-8 stainless steel construction, ideal for harsh environments and extended service life
• Precise and secure fastening ensured by the Class 3A thread fit, minimizing the risk of loosening under vibration
• High-strength performance with a Rockwell B80 hardness, providing reliable clamping force and resistance to wear
• Easy and flush installation with the headless design and 1/16" hex drive, allowing for a clean finish in confined spaces
• Superior grip and holding power from the cup tip, which digs into the mating surface to prevent component slippage
• Guaranteed dimensional accuracy and interchangeability, manufactured to meet the stringent ASME B18.3 standard
• Safe for regulated industries with full compliance to RoHS 3 and REACH environmental directives

Professional Applications & Engineering Value

This 6-40 UNF set screw is engineered to solve critical challenges in precision assembly and machinery. The 18-8 Stainless Steel material offers excellent resistance to rust and corrosion, making it suitable for applications exposed to moisture, chemicals, or outdoor conditions. The fine UNF thread and Class 3A fit provide a tighter tolerance than standard fits, which is crucial for maintaining alignment and preventing backlash in high-precision equipment like optical devices, aerospace components, and medical instruments. The headless design with a 1/16" hex drive allows for a low-profile installation, ideal for rotating shafts, collars, and pulleys where protruding fastener heads are not feasible. The cup tip concentrates pressure on a small area, creating a strong bite into the shaft to resist rotational forces and secure parts effectively without damaging the components.

Specification Summary & Compliance

This set screw features a 6-40 UNF fine thread with a Class 3A thread fit for high precision. It has a thread diameter of 0.138" and a length of 3/8". The manufacturing and dimensional standards comply with ASME B18.3. It is also confirmed to be RoHS 3 (2015/863/EU) Compliant and REACH (EC 1907/2006) Compliant, ensuring it meets current environmental and safety regulations for hazardous substances.