S-90251A181 1/4"-20 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 chemical exposure
• Permanent vibration resistance provided by the Nylon Patch thread locker, maintaining secure fastening from -50° to 250°F
• High-precision thread engagement with Class 3A fit for reliable, slop-free assembly and consistent clamping force
• Optimized torque transmission through the 1/8" hex drive, reducing tool slippage and installation damage
• Space-saving headless design allows for flush mounting in confined assemblies and rotating components
• Enhanced grip and minimal surface damage from the cup point tip, ensuring superior holding power on shafts and hubs
• Long-term mechanical durability supported by Rockwell B80 hardness, resisting wear and deformation under load

Professional Applications & Engineering Value

This 1/4"-20 UNC set screw is engineered to solve critical challenges in industrial assembly where vibration loosening and corrosion are major concerns. The 316 Stainless Steel material provides exceptional resistance to chemicals, moisture, and high temperatures, making it suitable for marine, food processing, and chemical equipment. The Nylon Patch thread locker offers a permanent locking solution without requiring secondary adhesives, ensuring maintained clamp load in high-vibration applications like motors, pulleys, and machinery. Combined with the headless design and cup point tip, it delivers reliable positioning of gears and collars on shafts, preventing axial movement while minimizing damage to the engaged surface. This fastener is ideal for precision mechanical systems demanding corrosion-resistant and vibration-proof performance.

Specification Summary & Compliance

This set screw features a 1/4"-20 UNC coarse thread with Class 3A thread fit for high precision and strength. It complies with ASME B18.3 standards for dimensional consistency and performance. The product is RoHS 3 (2015/863/EU) Compliant and REACH (EC 1907/2006) Compliant, ensuring it meets environmental and safety regulations for hazardous substances. Manufacturing adheres to specified parameters including right-hand thread direction, hex drive size of 1/8", and a length of 3/16".