Cup Point Alloy Steel Socket Set Screws with Nylon Insert

Cup point alloy steel 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 alloy steel, these socket set screws are intended for demanding industrial mechanical applications requiring dependable positioning and fastening performance. They are commonly used to secure collars, hubs, gears, pulleys, sprockets, couplings, knobs, handles, and other shaft-mounted components in machinery, automation equipment, conveyors, power transmission systems, industrial tooling, 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 cup point alloy steel 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 to support accurate specification.

Why Choose Cup Point Alloy Steel 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.
  • Alloy steel construction: Intended for demanding industrial mechanical applications.
  • 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 requirements of the completed assembly. Cup point socket set screws should not be substituted automatically for flat point, cone point, oval point, half dog point, full dog point, or knurled cup point designs because each point geometry serves a different mechanical purpose.

Cold Headers Inc. has supplied specialty industrial socket fasteners since 1962. Our catalog helps engineers, distributors, maintenance professionals, and purchasing teams locate exact sizes, uncommon lengths, and difficult-to-find alloy steel 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 Alloy Steel Socket Set Screw with Nylon Insert
List Price (per 100 pieces) $89.00
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4-40 x 1/4 Cup Point Alloy Steel Socket Set Screw with Nylon Insert
List Price (per 100 pieces) $81.00
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4-40 x 5/16 Cup Point Alloy Steel Socket Set Screw with Nylon Insert
List Price (per 100 pieces) $81.25
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4-40 x 3/8 Cup Point Alloy Steel Socket Set Screw with Nylon Insert
List Price (per 100 pieces) $81.50
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4-40 x 7/16 Cup Point Alloy Steel Socket Set Screw with Nylon Insert
List Price (per 100 pieces) $81.75
Description N/A

4-40 x 3/16 Cup Point Alloy Steel Socket Set Screw with Nylon Insert combines a cup point, internal hex drive, and nylon locking pellet in one headless fastener. The cup rim seats against the mating surface, while the nylon insert develops prevailing torque in the female thread.

Typical uses include collars and couplings on production machinery where a shaft-mounted component must stay adjusted. Confirm thread size, length, hex key size, cup point geometry, pellet diameter, and pellet location before substituting another set screw.

Cold Headers has supplied specialty socket fasteners since 1962 and helps buyers identify exact thread and length combinations. Nylon inserts are installed in-house at the Cold Headers facility in Chicago for this locking set screw family.

Technical Highlights

  • Point: Cup (approximately 0.55-0.62 x nominal diameter)
  • Material: Alloy 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 Alloy Steel Socket Set Screw with Nylon Insert is built for settings where the cup rim and thread friction both matter. That pairing helps the screw resist loosening through friction without replacing the mechanical holding role of the cup point.

Gear and sprocket retention often calls for a cup point where the screw bears into a hub or shaft feature. Confirm thread size, length, hex key size, cup point geometry, pellet diameter, and pellet location before substituting another set screw.

Cold Headers supports distributors, maintenance crews, and OEM buyers with carefully identified nylon-insert set screw sizes.

Technical Highlights

  • Point: Cup (approximately 0.55-0.62 x nominal diameter)
  • Material: Alloy 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 Alloy Steel Socket Set Screw with Nylon Insert gives shaft-mounted parts two forms of holding action: point contact and nylon pellet drag. The nylon pellet works in the thread path, so it is different from a nylon tip that is intended to contact the shaft surface.

Pulley and sheave shafts can use this style when an internal hex drive and locking thread feature are both specified. Confirm thread size, length, hex key size, cup point geometry, pellet diameter, and pellet location before substituting another set screw.

For unusual lengths or deeper alloy sizes, Cold Headers keeps the part defined by thread, length, point style, drive, and locking feature. A nylon tip protects the shaft surface; a nylon insert locks the screw in its thread, so nylon and brass tip set screws solve a different problem.

Technical Highlights

  • Point: Cup (approximately 0.55-0.62 x nominal diameter)
  • Material: Alloy 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.

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For production equipment that needs a locking cup point, the 4-40 x 3/8 Cup Point Alloy Steel Socket Set Screw with Nylon Insert keeps the thread and length explicit. The internal hex drive keeps installation compact while the pellet adds resistance during installation and removal.

Vibratory feeders and screens may require an alloy locking set screw where repeated motion makes thread friction useful. Confirm thread size, length, hex key size, cup point geometry, pellet diameter, and pellet location before substituting another set screw.

Cold Headers can help quote the requested cup point alloy size without substituting a different point geometry or head style. When a listed size is not the right fit, in-house pelletizing lets Cold Headers quote other set screw configurations. For wet or washdown service, the related 18-8 stainless cup point set screw with nylon insert is the corrosion-focused catalog choice.

Technical Highlights

  • Point: Cup (approximately 0.55-0.62 x nominal diameter)
  • Material: Alloy 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.

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4-40 x 7/16 Cup Point Alloy Steel Socket Set Screw with Nylon Insert is the alloy version of a self-locking cup point set screw for machinery work. The cup point is selected for localized holding contact; final selection still depends on shaft material, load, and access.

Gearbox and drive adjustments can use this family when a cup point holds position and the nylon insert adds prevailing torque. Confirm thread size, length, hex key size, cup point geometry, pellet diameter, and pellet location before substituting another set screw.

Since 1962, Cold Headers has helped industrial buyers source specialty socket products for repair, replacement, and production needs. Knurled point alloy socket set screws provide an all-metal ratchet-style grip where a nylon insert is not the desired locking method.

Technical Highlights

  • Point: Cup (approximately 0.55-0.62 x nominal diameter)
  • Material: Alloy Steel
  • Thread Size: 4-40
  • Length: 7/16 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.
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 7/16 in
Material N/A Nylon
Quantity N/A 100
Package Type N/A Box
Note N/A Less Than Package Quantity Specified Plus 25%.