Brass Button Head Socket Cap Screws

Cold Headers supplies brass button head socket cap screws in a broad range of thread sizes and lengths for applications that benefit from a low-profile rounded head, internal hex drive, and non-ferrous brass construction.

These fasteners are commonly used in electrical assemblies, instrumentation, control equipment, commercial fixtures, lighting equipment, laboratory hardware, machine covers, brackets, access panels, and other visible or compact assemblies. The rounded button-head profile provides reduced head projection and a smooth exposed appearance, while the internal hex socket supports positive tool engagement where external wrench clearance is limited.

Brass is often selected where electrical conductivity, non-magnetic properties, machinability, general corrosion resistance, or appearance are important design considerations. Brass button head socket cap screws are generally better suited to light- and moderate-duty fastening than applications requiring the strength of heat-treated alloy steel.

Our online catalog includes many commonly requested brass button head socket cap screw sizes, but it does not represent every configuration Cold Headers can supply. Additional non-catalog sizes, special lengths, and difficult-to-source items may be available by request.

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

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4-40 x 1/4 Brass Button Head Socket Cap Screw
List Price (per 100 pieces) $30.00
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4-40 x 3/8 Brass Button Head Socket Cap Screw
List Price (per 100 pieces) $32.00
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4-40 x 1/2 Brass Button Head Socket Cap Screw
List Price (per 100 pieces) $34.00
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4-40 x 5/8 Brass Button Head Socket Cap Screw
List Price (per 100 pieces) $35.00
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4-40 x 3/4 Brass Button Head Socket Cap Screw
List Price (per 100 pieces) $36.00
Description N/A

4-40 x 1/4 Brass Button Head Socket Cap Screw is specified where engineers want a smooth exposed head, socket-drive access, and the electrical advantages of non-ferrous construction. The button-head geometry is chosen for reduced head projection and a smooth exposed appearance while keeping the head visible and accessible. Engineers choose brass here for electrical conductivity, non-magnetic behavior, and non-ferrous construction rather than high-strength structural loading.

Appropriate uses include electrical assemblies and control panels, where conductivity and non-magnetic construction can be useful around selected hardware and instrumentation layouts. It can also fit electronic equipment and display hardware, where a decorative appearance and lower head projection help exposed hardware look intentional. The internal hex drive supports socket-key installation in compact equipment without relying on an external wrenching surface.

For the 4-40 thread and 1/4 in. length, the reference head diameter is 0.201-0.213 in. and the head height is 0.051-0.059 in. Use the verified dimensions below when checking head projection, socket access, and replacement fit.

Technical Highlights

  • Material: Brass
  • Thread Size: 4-40
  • Length: 1/4 in.
  • Nominal Body Diameter: #4 (.112 in.)
  • Head Diameter: 0.201-0.213 in.
  • Head Height: 0.051-0.059 in.
  • Hex-Key Size: 1/16 in.
  • Drive Type: Internal Hex

Reference dimensions may vary slightly by manufacturer.

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

4-40 x 3/8 Brass Button Head Socket Cap Screw supports low-load assemblies that need a rounded button head along with electrical conductivity and non-magnetic material behavior. Compared with taller head styles, the rounded button head can reduce snag potential on panels, covers, and handled surfaces. The material is often selected when conductivity, machinability, and appearance are more relevant than the strength profile of alloy steel.

Appropriate uses include instrumentation and precision equipment, where the finished button head keeps visible fastening points smooth while the material machines cleanly. It can also fit machine covers and automation equipment, where internal hex drive access supports installation where side clearance for external tooling is limited. The internal hex drive supports socket-key installation in compact equipment without relying on an external wrenching surface.

For the 4-40 thread and 3/8 in. length, the reference head diameter is 0.201-0.213 in. and the head height is 0.051-0.059 in. Use the verified dimensions below when checking head projection, socket access, and replacement fit.

Technical Highlights

  • Material: Brass
  • Thread Size: 4-40
  • Length: 3/8 in.
  • Nominal Body Diameter: #4 (.112 in.)
  • Head Diameter: 0.201-0.213 in.
  • Head Height: 0.051-0.059 in.
  • Hex-Key Size: 1/16 in.
  • Drive Type: Internal Hex

Reference dimensions may vary slightly by manufacturer.

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

4-40 x 1/2 Brass Button Head Socket Cap Screw is used where reduced head projection and a clean visible appearance are important on brass hardware. The internal hex drive keeps the installation tool inside the head, which is useful when external wrench clearance is limited. Brass is appropriate for many low-load mechanical assemblies where corrosion resistance in general service, appearance, and electrical behavior matter.

Appropriate uses include electronic equipment and display hardware, where a decorative appearance and lower head projection help exposed hardware look intentional. It can also fit electrical assemblies and control panels, where conductivity and non-magnetic construction can be useful around selected hardware and instrumentation layouts. The internal hex drive supports socket-key installation in compact equipment without relying on an external wrenching surface.

For the 4-40 thread and 1/2 in. length, the reference head diameter is 0.201-0.213 in. and the head height is 0.051-0.059 in. Use the verified dimensions below when checking head projection, socket access, and replacement fit.

Technical Highlights

  • Material: Brass
  • Thread Size: 4-40
  • Length: 1/2 in.
  • Nominal Body Diameter: #4 (.112 in.)
  • Head Diameter: 0.201-0.213 in.
  • Head Height: 0.051-0.059 in.
  • Hex-Key Size: 1/16 in.
  • Drive Type: Internal Hex

Reference dimensions may vary slightly by manufacturer.

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

4-40 x 5/8 Brass Button Head Socket Cap Screw helps designers combine a compact rounded head profile with material properties useful for electrical and instrumentation work. The broader bearing surface can be helpful on covers, light brackets, and equipment panels where the head remains visible. The material supports clean machining and a finished look for commercial hardware, instruments, and visible assemblies.

Appropriate uses include laboratory equipment and commercial fixtures, where non-ferrous construction and a clean exposed head are often preferred over plain steel hardware. It can also fit laboratory equipment and commercial fixtures, where non-ferrous construction and a clean exposed head are often preferred over plain steel hardware. The internal hex drive supports socket-key installation in compact equipment without relying on an external wrenching surface.

For the 4-40 thread and 5/8 in. length, the reference head diameter is 0.201-0.213 in. and the head height is 0.051-0.059 in. Use the verified dimensions below when checking head projection, socket access, and replacement fit.

Technical Highlights

  • Material: Brass
  • Thread Size: 4-40
  • Length: 5/8 in.
  • Nominal Body Diameter: #4 (.112 in.)
  • Head Diameter: 0.201-0.213 in.
  • Head Height: 0.051-0.059 in.
  • Hex-Key Size: 1/16 in.
  • Drive Type: Internal Hex

Reference dimensions may vary slightly by manufacturer.

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

4-40 x 3/4 Brass Button Head Socket Cap Screw is selected for exposed fastening points where appearance, machinability, and internal hex access matter more than high-strength fastening. This head style is a practical choice where the fastener should remain accessible while presenting a compact rounded profile. Because brass is non-ferrous, it can be useful in selected electrical, instrument, and laboratory applications where magnetic response is undesirable.

Appropriate uses include architectural hardware and commercial brass components, where the rounded head provides a finished appearance on visible covers and trim. It can also fit maintenance work and assembly operations, where the exact thread and length help match drawings, repair lists, and existing brass hardware. The internal hex drive supports socket-key installation in compact equipment without relying on an external wrenching surface.

For the 4-40 thread and 3/4 in. length, the reference head diameter is 0.201-0.213 in. and the head height is 0.051-0.059 in. Use the verified dimensions below when checking head projection, socket access, and replacement fit.

Technical Highlights

  • Material: Brass
  • Thread Size: 4-40
  • Length: 3/4 in.
  • Nominal Body Diameter: #4 (.112 in.)
  • Head Diameter: 0.201-0.213 in.
  • Head Height: 0.051-0.059 in.
  • Hex-Key Size: 1/16 in.
  • Drive Type: Internal Hex

Reference dimensions may vary slightly by manufacturer.

Call 773-775-7900 or email Sales@coldheaders.com for pricing, availability, or a quote.
Brands N/A Cold Headers, Inc.
Diameter N/A 4-40
Length N/A 1/4 in N/A 3/8 in N/A 1/2 in N/A 5/8 in N/A 3/4 in
Material N/A Brass
Quantity N/A 100
Package Type N/A Box