4-40 x 1/4 Alloy Steel Socket Head Cap Screw with Nylon Insert helps engineers address vibration-related loosening while retaining internal hex drive access for assembly work. Alloy steel construction and internal hex drive access support machine-building applications that still require practical installation. The insert feature should be matched to the mating hardware and service conditions specified for the assembly. Cold Headers also identifies this nylon insert socket head cap screw family with the 1960 Series. The 4-40 x 1/4 size supports exact catalog selection for machine guards, equipment covers, panels, brackets, and manufacturing workcells. 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. Industrial distributors, purchasing teams, maintenance professionals, and machine builders 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.