1/4-28 x 3/8 Alloy Steel Button Head Socket Cap Screw with Nylon Insert gives OEM equipment builders a button head socket cap screw option for vibration-related applications. The nylon insert provides prevailing-torque resistance that can help reduce loosening in machinery subject to vibration or repeated movement. This feature is useful for OEM equipment, automation systems, covers, guards, and service locations where joint retention matters. The 1/4-28 x 3/8 size supports exact catalog selection for OEM production, distributor stock programs, plant maintenance, and repair departments. For engineers, OEM manufacturers, purchasing managers, and maintenance professionals, this alloy steel part helps match the fastener to the assembly without changing the locked dimensions. Machine building, tooling, fixtures, automation equipment, and oem machinery are common sourcing contexts for this product family. Call Cold Headers at 773-775-7900 or email Sales@coldheaders.com for pricing, availability, or a quote.