18-8 Stainless Steel Button Head Socket Cap Screws with Nylon Insert

18-8 stainless steel button head socket cap screws with nylon insert combine a low-profile button head design with a factory-installed nylon locking element that provides prevailing torque during installation. The rounded button head offers a broad bearing surface with a smooth finished appearance, while the internal hex drive allows installation where external wrench clearance is limited. The nylon insert helps increase resistance to thread loosening caused by vibration, repeated movement, and dynamic loading.

Manufactured from 18-8 stainless steel, these fasteners provide general corrosion resistance for many industrial environments exposed to moisture, humidity, or routine washdown. They are commonly specified for machinery, automation equipment, robotics, conveyor systems, industrial enclosures, electronic equipment, instrumentation, panels, fixtures, maintenance repairs, and OEM assemblies where corrosion resistance and additional thread retention are desired.

Button head socket cap screws are frequently selected where a lower head profile and larger bearing surface are preferred over a standard socket head cap screw. Proper fastener selection should consider thread size, screw length, head diameter, head height, hex socket size, mating-thread engagement, installation access, and service conditions. The nylon insert provides prevailing torque but should not be considered a substitute for proper joint design or installation practices.

Cold Headers supplies 18-8 stainless 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, nominal body diameter, head diameter, head height, hex socket size, and additional engineering information where available.

Why Choose Button Head Socket Cap Screws with Nylon Insert?

  • Factory-installed nylon insert: Provides prevailing torque to help resist thread loosening.
  • 18-8 stainless steel: Offers general corrosion resistance for many industrial environments.
  • Low-profile button head: Provides a smooth appearance with a broad bearing surface.
  • Internal hex drive: Allows installation where external wrench clearance is limited.
  • Verified engineering dimensions: Product pages provide thread size, length, head dimensions, and hex socket size where available.

Selecting the Correct 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 clearance, operating environment, and assembly requirements before selecting a fastener. Final selection should reflect the mechanical loading, environmental conditions, 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.

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4-40 x 1/4 18-8 Stainless Steel Button Head Socket Cap Screw with Nylon Insert
List Price (per 100 pieces) $92.50
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4-40 x 3/8 18-8 Stainless Steel Button Head Socket Cap Screw with Nylon Insert
List Price (per 100 pieces) $93.00
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4-40 x 1/2 18-8 Stainless Steel Button Head Socket Cap Screw with Nylon Insert
List Price (per 100 pieces) $93.50
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4-40 x 5/8 18-8 Stainless Steel Button Head Socket Cap Screw with Nylon Insert
List Price (per 100 pieces) Call or Email for Pricing
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4-40 x 3/4 18-8 Stainless 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 18-8 Stainless Steel Button Head Socket Cap Screw with Nylon Insert uses a low-dome head for exposed fastening where a smooth, reduced-profile shape matters. The nylon pellet presses against the mating thread for prevailing torque without changing the head geometry.

The rounded button head can reduce exposed edges, spread bearing load over a broader face, and avoid counterbore machining when the assembly accepts a raised dome. Typical applications include machine guards, removable covers, and service panels, where exposed hardware benefits from a smooth dome and exact thread-length match.

The 18% chromium and 8% nickel austenitic stainless material is commonly chosen for general corrosion resistance, clean appearance, and ordinary moisture exposure. For chloride-heavy or saltwater-adjacent service, 316 stainless with nylon insert is a non-catalog request Cold Headers can quote. Cold Headers has supplied specialty socket fasteners since 1962 and helps buyers source exact stainless sizes and uncommon lengths.

Technical Highlights

  • Material: 18-8 Stainless Steel
  • Thread Size: 4-40
  • Length: 1/4 in.
  • Head Style: Button Head
  • Drive Type: Internal Hex
  • Locking Feature: Nylon insert providing prevailing torque
  • Nylon Insert Diameter (P): 1/16 in.
  • Nylon Insert Location (N): 7/64 in. +/-1/2 pitch
  • Head Dimensions: ASME B18.3

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

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4-40 x 3/8 18-8 Stainless Steel Button Head Socket Cap Screw with Nylon Insert brings stainless material and a nylon locking pellet to equipment that sees ordinary moisture or cleaning. The nylon pellet presses against the mating thread for prevailing torque without changing the head geometry.

The rounded button head can reduce exposed edges, spread bearing load over a broader face, and avoid counterbore machining when the assembly accepts a raised dome. In food equipment panels, washdown covers, or stainless frame hardware, the internal hex drive supports top-side installation while the rounded head reduces surface projection.

The 18% chromium and 8% nickel austenitic stainless material is commonly chosen for general corrosion resistance, clean appearance, and ordinary moisture exposure. For higher preload potential with a deeper socket, compare 18-8 Socket Head Cap Screws with Nylon Insert. Nylon inserts are installed in-house at the Chicago facility for supported cap-screw configurations.

Technical Highlights

  • Material: 18-8 Stainless Steel
  • Thread Size: 4-40
  • Length: 3/8 in.
  • Head Style: Button Head
  • Drive Type: Internal Hex
  • Locking Feature: Nylon insert providing prevailing torque
  • Nylon Insert Diameter (P): 1/16 in.
  • Nylon Insert Location (N): 7/64 in. +/-1/2 pitch
  • Head Dimensions: ASME B18.3

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

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4-40 x 1/2 18-8 Stainless Steel Button Head Socket Cap Screw with Nylon Insert combines internal hex drive access with a thread-mounted nylon pellet for prevailing torque. The nylon pellet presses against the mating thread for prevailing torque without changing the head geometry.

Button head geometry is useful around access covers, machine guards, and operator-contact surfaces where a smooth exposed profile is preferred. This size is often reviewed for conveyor side rails, guide brackets, and packaging-line guards when stainless material, a button head, and a locking pellet are all specified.

The 18% chromium and 8% nickel austenitic stainless material is commonly chosen for general corrosion resistance, clean appearance, and ordinary moisture exposure. For higher preload potential with a deeper socket, compare 18-8 Socket Head Cap Screws with Nylon Insert. Since 1962, Cold Headers has helped industrial buyers locate specialty socket products for production, repair, and replacement requirements.

Technical Highlights

  • Material: 18-8 Stainless Steel
  • Thread Size: 4-40
  • Length: 1/2 in.
  • Head Style: Button Head
  • Drive Type: Internal Hex
  • Locking Feature: Nylon insert providing prevailing torque
  • Nylon Insert Diameter (P): 1/16 in.
  • Nylon Insert Location (N): 7/64 in. +/-1/2 pitch
  • Head Dimensions: ASME B18.3

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

 		N/A

4-40 x 5/8 18-8 Stainless Steel Button Head Socket Cap Screw with Nylon Insert gives guards, covers, and panels a rounded head that sits lower than a standard socket head cap screw. Its insert creates thread-friction resistance to backing out under vibration without requiring a separate locking washer.

Button head geometry is useful around access covers, machine guards, and operator-contact surfaces where a smooth exposed profile is preferred. For packaging machinery, changeover plates, or access doors, confirm the mating thread, drive access, and whether surface contact from the button head suits the assembly.

The 18% chromium and 8% nickel austenitic stainless material is commonly chosen for general corrosion resistance, clean appearance, and ordinary moisture exposure. For higher preload potential with a deeper socket, compare 18-8 Socket Head Cap Screws with Nylon Insert. Cold Headers can help confirm the correct 18-8 button head nylon-insert size before quoting pricing and availability.

Technical Highlights

  • Material: 18-8 Stainless Steel
  • Thread Size: 4-40
  • Length: 5/8 in.
  • Head Style: Button Head
  • Drive Type: Internal Hex
  • Locking Feature: Nylon insert providing prevailing torque
  • Nylon Insert Diameter (P): 1/16 in.
  • Nylon Insert Location (N): 7/64 in. +/-1/2 pitch
  • Head Dimensions: ASME B18.3

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

 		N/A

4-40 x 3/4 18-8 Stainless Steel Button Head Socket Cap Screw with Nylon Insert is selected where a clean stainless appearance and added thread friction are both useful. Its insert creates thread-friction resistance to backing out under vibration without requiring a separate locking washer.

Because the socket is shallower than a full socket head cap screw, compare 18-8 SHCS with Nylon Insert when clamp load and deeper drive engagement govern the joint. Typical applications include high-touch equipment surfaces, display hardware, and operator panels, where exposed hardware benefits from a smooth dome and exact thread-length match.

18-8 stainless is practical for washdown-adjacent machinery, packaging equipment, and outdoor or high-touch hardware where the service environment is not chloride-critical. For higher preload potential with a deeper socket, compare 18-8 Socket Head Cap Screws with Nylon Insert. For a non-catalog pellet size, Cold Headers can route supported special requests through in-house pelletizing.

Technical Highlights

  • Material: 18-8 Stainless Steel
  • Thread Size: 4-40
  • Length: 3/4 in.
  • Head Style: Button Head
  • Drive Type: Internal Hex
  • Locking Feature: Nylon insert providing prevailing torque
  • Nylon Insert Diameter (P): 1/16 in.
  • Nylon Insert Location (N): 7/64 in. +/-1/2 pitch
  • Head Dimensions: ASME B18.3

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 18-8 Stainless Steel
Quantity N/A 100