6-40 x 3 1/2 Alloy Steel Socket Head Cap Screw is a socket head cap screw for buyers matching an exact thread and length to drawings, repair records, or stocked hardware. The 6-40 thread and 3 1/2 in. length support matching drawings and maintenance records in machine frames and brackets. Selected for maintenance repair, precision assemblies, and machine tools, it gives maintenance teams a searchable alloy steel socket screw callout. Internal hex drive access helps installation in compact assemblies, guards, housings, and fixture plates. Those verified dimensions support counterbore checks, tool selection, and replacement fastener review. Technical Highlights Material: Alloy Steel Thread: 6-40 Length: 3 1/2 in. Nominal Body Diameter: .138 in. Head Diameter: 0.218 in. min / 0.226 in. max Head Height: 0.134 in. min / 0.138 in. max Hex Key Size: 7/64 Drive Type: Internal hex socket Call 773-775-7900 or email Sales@coldheaders.com for pricing, availability, or a quote.