Alloy Steel Button Head Socket Cap Screws with Nylon Insert

Alloy steel button head socket cap screws with nylon insert combine the low-profile, wide-bearing design of a button head socket screw with a factory-installed nylon locking element that provides prevailing torque during installation. The internal hex drive allows installation where external wrench clearance is limited, while the rounded button head offers a clean appearance and increased bearing surface compared to standard socket head cap screws.

The nylon insert increases resistance to thread loosening caused by vibration, repeated movement, and dynamic loading without requiring separate locking components. These fasteners are commonly specified for machinery, automation equipment, conveyor systems, robotics, industrial enclosures, electronic equipment, guarding, panels, fixtures, maintenance repairs, and OEM assemblies where both a low-profile head and additional thread retention are desirable.

Manufactured from alloy steel, these button head socket cap screws are intended for demanding mechanical applications. Proper selection should consider thread size, screw length, head clearance, mating-thread engagement, installation access, environmental conditions, and assembly requirements. The nylon insert provides prevailing torque but should not be considered a substitute for proper joint design or installation practices.

Cold Headers supplies alloy steel button head socket cap screws with nylon insert in a broad range of inch thread sizes and lengths, including uncommon and difficult-to-source configurations. Individual product pages provide verified thread size, screw length, head diameter, head height, hex socket size, and other dimensional information where available.

Why Choose a Button Head Socket Cap Screw with Nylon Insert?

  • Factory-installed nylon insert: Provides prevailing torque to help resist thread loosening.
  • Low-profile button head: Offers a smooth, rounded head with a broad bearing surface.
  • Internal hex drive: Supports installation where external wrench clearance is limited.
  • Alloy steel construction: Designed for demanding industrial mechanical applications.
  • Exact-size selection: Product pages provide verified thread size, length, head dimensions, and hex socket size where available.

Selecting the Correct Nylon Insert Button Head Socket Cap Screw

Begin by confirming the required thread size and screw length. Review the head diameter, head height, hex socket size, mating-thread specifications, installation access, and assembly requirements. Final fastener selection should reflect the mechanical loading, operating environment, and the desired level of prevailing torque for the application.

Cold Headers Inc. has supplied specialty industrial socket fasteners since 1962. Our catalog helps engineers, distributors, maintenance teams, and purchasing professionals locate exact sizes, uncommon lengths, and difficult-to-find button head socket cap screws with nylon insert without unsupported inventory claims.

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

Request Information Search by Specification
Unit of Measure
Items
button-head-socket-cap-screw-nylon-pellet-alloy.png

4-40 x 1/4 Alloy Steel Button Head Socket Cap Screw with Nylon Insert
List Price (per 100 pieces) $72.50
button-head-socket-cap-screw-nylon-pellet-alloy.png

4-40 x 3/8 Alloy Steel Button Head Socket Cap Screw with Nylon Insert
List Price (per 100 pieces) $72.75
button-head-socket-cap-screw-nylon-pellet-alloy.png

4-40 x 1/2 Alloy Steel Button Head Socket Cap Screw with Nylon Insert
List Price (per 100 pieces) $73.00
button-head-socket-cap-screw-nylon-pellet-alloy.png

4-40 x 5/8 Alloy Steel Button Head Socket Cap Screw with Nylon Insert
List Price (per 100 pieces) Call or Email for Pricing
button-head-socket-cap-screw-nylon-pellet-alloy.png

4-40 x 3/4 Alloy Steel Button Head Socket Cap Screw with Nylon Insert
List Price (per 100 pieces) Call or Email for Pricing
Description N/A

4-40 x 1/4 Alloy Steel Button Head Socket Cap Screw with Nylon Insert is a socket-driven fastener for assemblies that need a rounded low-profile head plus a built-in prevailing-torque feature. The nylon insert helps resist loosening through friction at the mating threads, providing prevailing torque without requiring a separate locking component.

The button head profile offers reduced head projection, a smooth exposed appearance, and a broad bearing surface compared with a standard cylindrical socket head. Typical uses include machine guards, equipment covers, and service panels, where a precise socket fastener with a low rounded head can support compact machinery layouts. Review thread size, length, mating material, available drive access, and whether the nylon insert is appropriate before release to production or repair work.

Cold Headers has supplied specialty socket fasteners since 1962 and supports exact-size sourcing for difficult-to-find socket products. For adjacent selections, buyers often compare standard Alloy Steel Button Head Socket Cap Screws, Alloy Steel Socket Head Cap Screws, and Alloy Steel Flat Head Socket Cap Screws when checking head style, material, locking feature, thread size, or nearby lengths.

Technical Highlights

  • Material: Alloy Steel
  • Thread Size: 4-40
  • Length: 1/4 in.
  • Head Style: Button Head
  • Drive Type: Internal Hex Socket
  • Locking Feature: Nylon insert providing prevailing torque

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

 		N/A

For drawings calling out a locking button head socket screw, the 4-40 x 3/8 Alloy Steel Button Head Socket Cap Screw with Nylon Insert keeps exact thread and length identification clear. The nylon insert helps resist loosening through friction at the mating threads, providing prevailing torque without requiring a separate locking component.

The button head profile offers reduced head projection, a smooth exposed appearance, and a broad bearing surface compared with a standard cylindrical socket head. In automation systems, robotic fixtures, and inspection tooling, the internal hex socket drive allows tool access from above while the nylon insert adds frictional resistance at the threads. Review thread size, length, mating material, available drive access, and whether the nylon insert is appropriate before release to production or repair work.

Cold Headers has supplied specialty socket fasteners since 1962 and supports exact-size sourcing for difficult-to-find socket products. For adjacent selections, buyers often compare 18-8 Stainless Button Head Socket Cap Screws, 316 Stainless Button Head Socket Cap Screws, and related locking fasteners when checking head style, material, locking feature, thread size, or nearby lengths.

Technical Highlights

  • Material: Alloy Steel
  • Thread Size: 4-40
  • Length: 3/8 in.
  • Head Style: Button Head
  • Drive Type: Internal Hex Socket
  • Locking Feature: Nylon insert providing prevailing torque

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

 		N/A

4-40 x 1/2 Alloy Steel Button Head Socket Cap Screw with Nylon Insert combines alloy steel construction, a smooth button head profile, an internal hex socket drive, and a nylon locking element. Its nylon insert creates frictional thread contact during installation, so the screw can be considered where service conditions call for added loosening resistance.

The button head profile offers reduced head projection, a smooth exposed appearance, and a broad bearing surface compared with a standard cylindrical socket head. The 4-40 x 1/2 size is often reviewed for industrial equipment, bracket assemblies, and machine frames when a bill of materials specifies an alloy steel locking button head socket screw. Review thread size, length, mating material, available drive access, and whether the nylon insert is appropriate before release to production or repair work.

Cold Headers has supplied specialty socket fasteners since 1962 and supports exact-size sourcing for difficult-to-find socket products. For adjacent selections, buyers often compare Nylon Insert Socket Head Cap Screws, Nylon Insert Set Screws, and nearby thread sizes when checking head style, material, locking feature, thread size, or nearby lengths.

Technical Highlights

  • Material: Alloy Steel
  • Thread Size: 4-40
  • Length: 1/2 in.
  • Head Style: Button Head
  • Drive Type: Internal Hex Socket
  • Locking Feature: Nylon insert providing prevailing torque

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

 		N/A

This 4-40 x 5/8 Alloy Steel Button Head Socket Cap Screw with Nylon Insert is intended for cataloged inch-size applications where a button head and nylon insert are both specified. Its nylon insert creates frictional thread contact during installation, so the screw can be considered where service conditions call for added loosening resistance.

Button head geometry is useful when clearance, appearance, and lower head height matter more than using a standard socket head cap screw profile. Typical uses include electronics enclosures, control panels, and access covers, where a precise socket fastener with a low rounded head can support compact machinery layouts. Review thread size, length, mating material, available drive access, and whether the nylon insert is appropriate before release to production or repair work.

Cold Headers has supplied specialty socket fasteners since 1962 and supports exact-size sourcing for difficult-to-find socket products. For adjacent selections, buyers often compare standard button head socket screws, flat head socket cap screws, and nearby lengths when checking head style, material, locking feature, thread size, or nearby lengths.

Technical Highlights

  • Material: Alloy Steel
  • Thread Size: 4-40
  • Length: 5/8 in.
  • Head Style: Button Head
  • Drive Type: Internal Hex Socket
  • Locking Feature: Nylon insert providing prevailing torque

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

 		N/A

4-40 x 3/4 Alloy Steel Button Head Socket Cap Screw with Nylon Insert is a socket-driven fastener for assemblies that need a rounded low-profile head plus a built-in prevailing-torque feature. The insert provides a prevailing-torque feature while preserving the compact top-side tool access expected from an internal hex button head screw.

Button head geometry is useful when clearance, appearance, and lower head height matter more than using a standard socket head cap screw profile. In packaging machinery, conveyor equipment, and production cells, the internal hex socket drive allows tool access from above while the nylon insert adds frictional resistance at the threads. Selection should account for joint geometry, thread engagement, installation access, head clearance, and the desired level of prevailing torque.

Cold Headers has supplied specialty socket fasteners since 1962 and supports exact-size sourcing for difficult-to-find socket products. For adjacent selections, buyers often compare standard Alloy Steel Button Head Socket Cap Screws, Alloy Steel Socket Head Cap Screws, and Alloy Steel Flat Head Socket Cap Screws when checking head style, material, locking feature, thread size, or nearby lengths.

Technical Highlights

  • Material: Alloy Steel
  • Thread Size: 4-40
  • Length: 3/4 in.
  • Head Style: Button Head
  • Drive Type: Internal Hex Socket
  • Locking Feature: Nylon insert providing prevailing torque

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 Alloy Steel
Quantity N/A 100
Package Type N/A Box
Note N/A Less Than Package Quantity Specified Plus 25%.