18-8 Stainless Steel Cup Point Socket Set Screws with Nylon Insert

18-8 stainless steel cup point socket set screws with nylon insert combine the holding characteristics of a cup point set screw with a factory-installed nylon locking element that provides prevailing torque during installation. The recessed cup point creates localized rim contact with the mating surface, while the nylon insert helps increase resistance to thread loosening caused by vibration, repeated movement, and dynamic loading. The internal hex drive allows installation where external wrench clearance is limited.

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 used to secure collars, hubs, gears, pulleys, sprockets, knobs, handles, couplings, and other shaft-mounted components in machinery, automation equipment, conveyors, instrumentation, processing equipment, maintenance repairs, and OEM assemblies.

Cup point geometry is frequently selected where concentrated contact with the mating surface is desired. Depending on the shaft material and installation conditions, the point may leave a witness mark or shallow indentation on the contacted surface. Proper fastener selection should consider thread size, screw length, hex socket size, mating material, installation access, acceptable surface marking, and the desired level of prevailing torque. 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 cup point socket set 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 diameter, hex socket size, cup point dimensions, and additional engineering information where available.

Why Choose Cup Point Socket Set Screws with Nylon Insert?

  • Factory-installed nylon insert: Provides prevailing torque to help resist thread loosening.
  • Cup point geometry: Creates localized rim contact with the mating surface.
  • 18-8 stainless steel: Offers general corrosion resistance for many industrial environments.
  • Internal hex drive: Allows installation where external wrench clearance is limited.
  • Verified engineering dimensions: Product pages provide thread size, length, nominal diameter, hex socket size, and cup point dimensions where available.

Selecting the Correct Cup Point Socket Set Screw

Begin by confirming the required thread size and screw length. Review the hex socket size, mating material, installation clearance, operating environment, acceptable surface marking, and assembly requirements before selecting a fastener. Final selection should reflect the mechanical and environmental requirements of the completed assembly.

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 socket set 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 3/16 Cup Point 18-8 Stainless Steel Socket Set Screw with Nylon Insert
List Price (per 100 pieces) $95.00
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4-40 x 1/4 Cup Point 18-8 Stainless Steel Socket Set Screw with Nylon Insert
List Price (per 100 pieces) $92.00
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4-40 x 5/16 Cup Point 18-8 Stainless Steel Socket Set Screw with Nylon Insert
List Price (per 100 pieces) $98.00
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4-40 x 3/8 Cup Point 18-8 Stainless Steel Socket Set Screw with Nylon Insert
List Price (per 100 pieces) $99.00
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4-40 x 1/2 Cup Point 18-8 Stainless Steel Socket Set Screw with Nylon Insert
List Price (per 100 pieces) Call or Email for Pricing
Description N/A

4-40 x 3/16 Cup Point 18-8 Stainless Steel Socket Set Screw with Nylon Insert uses two locking interfaces in one headless fastener. The cup point's hollow rim bears on the shaft or mating part, while the nylon insert presses against the female thread to help resist back-out. 18-8 stainless steel is commonly selected for clean appearance, general corrosion resistance, and ordinary moisture exposure.

Typical uses include collars and couplings on washdown conveyors, set collars, and shaft-mounted guides, where the set screw must hold position without an external head. For 316 stainless with a nylon insert, treat the requirement as a non-catalog request that Cold Headers can quote.

Cold Headers has supplied specialty socket fasteners since 1962 and helps confirm exact set screw sizes for drawings and repairs. Review the thread size, length, hex key size, point style, and set-screw pellet location before matching the part to a service record or drawing.

Technical Highlights

  • Point: Cup point, approx. 0.55-0.62 x nominal dia.
  • Material: 18-8 Stainless Steel
  • Thread Size: 4-40
  • Length: 3/16 in.
  • Drive: Internal Hex
  • Hex Key Size: 0.050 in.
  • Locking Feature: Nylon insert providing prevailing torque
  • Nylon Insert Diameter (P): 1/16 in.
  • Nylon Insert Location (N): 3/32 in. +/-1/2 pitch
  • Dimensional Standard: 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 1/4 Cup Point 18-8 Stainless Steel Socket Set Screw with Nylon Insert pairs a cup point for shaft contact with a nylon pellet in the thread. The cup point's hollow rim bears on the shaft or mating part, while the nylon insert presses against the female thread to help resist back-out. 18-8 stainless steel is commonly selected for clean appearance, general corrosion resistance, and ordinary moisture exposure.

For food and beverage machinery adjustments, changeover stops, or equipment guards, check point contact, threaded engagement, and drive access before installation. For torque-once settings without a pellet, compare 18-8 Socket Set Screws in the appropriate point style.

Nylon inserts are installed in-house at the Cold Headers Chicago facility for supported set-screw configurations. Review the thread size, length, hex key size, point style, and set-screw pellet location before matching the part to a service record or drawing.

Technical Highlights

  • Point: Cup point, approx. 0.55-0.62 x nominal dia.
  • Material: 18-8 Stainless Steel
  • Thread Size: 4-40
  • Length: 1/4 in.
  • Drive: Internal Hex
  • Hex Key Size: 0.050 in.
  • Locking Feature: Nylon insert providing prevailing torque
  • Nylon Insert Diameter (P): 1/16 in.
  • Nylon Insert Location (N): 3/32 in. +/-1/2 pitch
  • Dimensional Standard: 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 5/16 Cup Point 18-8 Stainless Steel Socket Set Screw with Nylon Insert is built for assemblies that need both cup-point holding action and prevailing torque. One interface helps hold the collar or hub against movement; the other adds friction in the thread so vibration is less likely to loosen the screw. 18-8 stainless steel is commonly selected for clean appearance, general corrosion resistance, and ordinary moisture exposure.

This size is often reviewed for pulleys and sprockets in humid plants, light drives, and hub retention when stainless material and thread locking are both specified. For torque-once settings without a pellet, compare 18-8 Socket Set Screws in the appropriate point style.

For distributors, OEM sourcing, and maintenance work, Cold Headers can help match the thread, length, point style, material, and insert location. Review the thread size, length, hex key size, point style, and set-screw pellet location before matching the part to a service record or drawing.

Technical Highlights

  • Point: Cup point, approx. 0.55-0.62 x nominal dia.
  • Material: 18-8 Stainless Steel
  • Thread Size: 4-40
  • Length: 5/16 in.
  • Drive: Internal Hex
  • Hex Key Size: 0.050 in.
  • Locking Feature: Nylon insert providing prevailing torque
  • Nylon Insert Diameter (P): 1/16 in.
  • Nylon Insert Location (N): 3/32 in. +/-1/2 pitch
  • Dimensional Standard: ASME B18.3

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

 		N/A

4-40 x 3/8 Cup Point 18-8 Stainless Steel Socket Set Screw with Nylon Insert gives a stainless, internal-hex set screw option for collars, hubs, and adjustments. One interface helps hold the collar or hub against movement; the other adds friction in the thread so vibration is less likely to loosen the screw. Use 18-8 stainless where the drawing calls for stainless material in indoor machinery, washdown-adjacent equipment, or humid service.

In packaging equipment, indexing stops, and machine adjustments, the internal hex drive allows adjustment from the end of the tapped hole. For torque-once settings without a pellet, compare 18-8 Socket Set Screws in the appropriate point style. This 18-8 family is not a heat-treated alloy-steel substitute; review the alloy version where seating torque is the priority.

Cold Headers brings long-running socket fastener knowledge to cup point set screw quoting and cross-checking. Review the thread size, length, hex key size, point style, and set-screw pellet location before matching the part to a service record or drawing.

Technical Highlights

  • Point: Cup point, approx. 0.55-0.62 x nominal dia.
  • Material: 18-8 Stainless Steel
  • Thread Size: 4-40
  • Length: 3/8 in.
  • Drive: Internal Hex
  • Hex Key Size: 0.050 in.
  • Locking Feature: Nylon insert providing prevailing torque
  • Nylon Insert Diameter (P): 1/16 in.
  • Nylon Insert Location (N): 3/32 in. +/-1/2 pitch
  • Dimensional Standard: ASME B18.3

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

 		N/A

4-40 x 1/2 Cup Point 18-8 Stainless Steel Socket Set Screw with Nylon Insert places the cup rim at the workpiece and the nylon insert at the mating thread. The point focuses contact at the work surface, and the pellet creates prevailing torque after the screw is driven into the tapped hole. Use 18-8 stainless where the drawing calls for stainless material in indoor machinery, washdown-adjacent equipment, or humid service.

Typical uses include pump and mixer shafts, drive collars, and equipment repairs, where the set screw must hold position without an external head. For torque-once settings without a pellet, compare 18-8 Socket Set Screws in the appropriate point style.

Need the pellet in a non-catalog size? Cold Headers can review supported in-house pelletizing requests. Review the thread size, length, hex key size, point style, and set-screw pellet location before matching the part to a service record or drawing.

Technical Highlights

  • Point: Cup point, approx. 0.55-0.62 x nominal dia.
  • Material: 18-8 Stainless Steel
  • Thread Size: 4-40
  • Length: 1/2 in.
  • Drive: Internal Hex
  • Hex Key Size: 0.050 in.
  • Locking Feature: Nylon insert providing prevailing torque
  • Nylon Insert Diameter (P): 1/16 in.
  • Nylon Insert Location (N): 3/32 in. +/-1/2 pitch
  • Dimensional Standard: 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 3/16 in N/A 1/4 in N/A 5/16 in N/A 3/8 in N/A 1/2 in
Material N/A 18-8 Stainless Steel
Quantity N/A 100
Package Type N/A Box