S-98057A658 1/4"-20 x 3/8" 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
• Maximum holding power and vibration resistance thanks to the cup point design that bites into shafts for a secure, non-slip grip
• Precise and reliable thread engagement ensured by Class 2A thread fit, reducing the risk of cross-threading and assembly failures
• Optimized for high-strength applications with a Rockwell B80 hardness, providing excellent durability and resistance to wear
• Easy installation and adjustment with a standard slotted drive, compatible with common hand tools for efficient maintenance
• Space-saving headless design allows for flush mounting in assemblies where protruding fastener heads are not feasible
• Full regulatory compliance with ASME B18.3, RoHS 3, and REACH, ensuring safety and environmental standards are met for global supply chains

Professional Applications & Engineering Value

This 1/4"-20 UNC set screw is engineered to solve critical challenges in precision assembly and motion control systems. The 316 Stainless Steel material offers exceptional resistance to chemicals, saltwater, and industrial atmospheres, preventing premature failure in demanding applications like marine equipment, food processing machinery, and chemical plants. The headless, slotted design combined with a coarse UNC thread and cup point ensures deep penetration and a permanent lock on pulleys, gears, and collars, effectively countering loosening from vibrations. This makes it an indispensable component for engineers requiring reliable, long-term fastening in high-torque, right-hand thread applications where disassembly is infrequent but security is paramount.

Specification Summary & Compliance

This set screw features a 1/4"-20 UNC coarse thread with a Class 2A thread fit for consistent dimensional accuracy and ease of assembly. It measures 0.25" in thread diameter and 3/8" in length with a right-hand thread direction. Manufactured in compliance with ASME B18.3 specifications, it also meets RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) environmental regulations, ensuring it is free from hazardous substances and suitable for use in regulated industries.