4-40 x 3/4 Brass Flat Head Socket Cap Screw is intended for applications where brass material and flat-head socket geometry are both called out by the drawing or bill of materials.

This head style differs from button head, low head, and cylindrical socket head screws because the head is designed to nest into a matching countersunk seat. Typical uses include fixtures, housings, and low-load mechanical assemblies, where reduced projection, socket-drive access, and a clean exposed surface can matter.

The material is often selected where the assembly requires brass hardware for electrical equipment, controls, instrumentation, or appearance-sensitive components. For this 4-40 thread and 3/4 in. length, review the body diameter, head diameter, head height, hex socket size, and key engagement before approving the fastener for a countersunk assembly. Cold Headers helps industrial distributors, sourcing teams, and maintenance operations identify uncommon lengths and specialty socket products.

Technical Highlights

• Material: Brass
• Thread Size: 4-40
• Length: 3/4 in.
• Nominal Body Diameter: 0.112 in.
• Head Diameter: 0.218-0.255 in.
• Head Height: 0.083 in.
• Hex Socket Size: 1/16 in.
• Drive Type: Internal Hex
• Minimum Key Engagement: 0.055 in.

Call 773-775-7900 or email Sales@coldheaders.com for pricing, availability, or a quote.