S-95289A139 1/4"-20 x 1" ASME B18.3 Set Screws

Key Features & Benefits at a Glance

• Exceptional corrosion resistance with 18-8 stainless steel construction, ensuring long-term reliability in harsh environments
• Superior vibration resistance due to the extended tip design that creates deeper seating and prevents loosening under dynamic loads
• Precise thread engagement with Class 3A fit providing tighter tolerances for more secure fastening in critical applications
• High mechanical strength with Rockwell B80 hardness rating, offering excellent durability and wear resistance
• Optimized installation efficiency through hex drive design allowing high torque application without head interference
• Reliable performance standardization with ASME B18.3 compliance ensuring consistent quality and dimensional accuracy
• Environmental responsibility with RoHS 3 and REACH compliance, meeting strict international regulatory standards

Professional Applications & Engineering Value

This 1/4"-20 UNC hex headless set screw delivers critical engineering solutions where space constraints and vibration resistance are paramount. The 18-8 stainless steel composition provides excellent corrosion resistance for outdoor equipment, marine components, and food processing machinery. The extended tip design ensures positive seating in shaft collars, pulleys, and gears, preventing rotational slippage in high-torque applications. With coarse UNC threads and Class 3A thread fit, this fastener maintains secure positioning in aluminum and soft metals while resisting vibration-induced loosening. The headless configuration allows flush mounting in confined spaces where protruding fasteners would interfere with mechanical operation.

Specification Summary & Compliance

This set screw features precision 1/4"-20 UNC coarse threads with Class 3A thread fit for superior dimensional accuracy. Manufacturing conforms to ASME B18.3 specifications, ensuring consistent performance across industrial applications. The extended tip maintains tight tolerances with tip diameter of 0.156" (-0.007" to 0") and tip length of 0.134" (-0.005" to 0"). The product is fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) environmental regulations, containing no restricted substances.