18-8 Stainless Steel Metric Socket Head Cap Screws

18-8 stainless steel metric socket head cap screws are precision threaded fasteners featuring a cylindrical head and an internal hex drive for secure fastening in compact mechanical assemblies. Their metric thread sizes make them well suited for internationally designed equipment, while the internal hex socket allows installation where external wrench clearance is limited. These fasteners are commonly used in industrial machinery, automation equipment, robotics, tooling, fixtures, conveyors, machine tools, maintenance repairs, and OEM manufacturing.

Manufactured from 18-8 stainless steel, these metric socket head cap screws provide general corrosion resistance for many industrial environments exposed to moisture, humidity, or routine washdown. They are commonly specified for equipment utilizing metric fasteners where stainless steel construction is preferred together with the compact profile and installation advantages of an internal hex drive.

Proper fastener selection should consider metric thread size, screw length, nominal body diameter, head diameter, head height, hex socket size, mating-thread engagement, installation clearance, and service environment. Individual product pages provide verified engineering dimensions to assist engineers and purchasing professionals in selecting the correct fastener for demanding industrial applications.

Cold Headers supplies 18-8 stainless steel metric socket head cap screws in a broad range of metric thread sizes and lengths, including standard, uncommon, and difficult-to-source configurations. Our catalog is organized to simplify exact-size sourcing while providing consistent engineering information across every product family.

Why Choose 18-8 Stainless Steel Metric Socket Head Cap Screws?

  • Metric thread sizes: Designed for equipment utilizing metric fasteners.
  • Cylindrical socket head: Compact design for applications with limited installation space.
  • Internal hex drive: Allows installation using standard metric hex keys or hex bits.
  • 18-8 stainless steel: Provides general corrosion resistance for many industrial environments.
  • Verified engineering dimensions: Product pages provide metric thread size, screw length, body diameter, head diameter, head height, and hex socket size where available.

Selecting the Correct Metric Socket Head Cap Screw

Begin by confirming the required metric thread size and screw length. Review the body diameter, head diameter, head height, hex socket size, installation clearance, mating-thread engagement, and operating environment before selecting a fastener. Final material 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 professionals, and purchasing teams locate exact metric sizes, uncommon lengths, and difficult-to-find socket head cap screws without unsupported inventory claims.

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

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M3-0.5 x 5 18-8 Stainless Steel Metric Socket Head Cap Screw
List Price (per 100 pieces) $9.00
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M3-0.5 x 6 18-8 Stainless Steel Metric Socket Head Cap Screw
List Price (per 100 pieces) $9.05
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M3-0.5 x 8 18-8 Stainless Steel Metric Socket Head Cap Screw
List Price (per 100 pieces) $9.10
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M3-0.5 x 10 18-8 Stainless Steel Metric Socket Head Cap Screw
List Price (per 100 pieces) $9.15
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M3-0.5 x 12 18-8 Stainless Steel Metric Socket Head Cap Screw
List Price (per 100 pieces) $9.20
Description N/A

M3-0.5 x 5 18-8 Stainless Steel Metric Socket Head Cap Screw is an 18-8 stainless steel metric socket head cap screw for equipment built around metric drawings. The socket head form is common in machinery where strong tool engagement and compact radial clearance are needed. The chromium-nickel stainless family resists rust and staining better than uncoated plain or alloy steel in many plant environments.

Chemical dosing skids and pump-adjacent equipment may use 18-8 where the actual exposure is within the material's limits. On many metric drawings, A2 stainless identifies the same broad chromium-nickel stainless family commonly called 18-8 in North America. For metric prints where clamp strength matters more than stainless corrosion performance, compare Alloy Steel Metric Socket Head Cap Screws.

Cold Headers helps buyers keep material, metric pitch, length, and socket head geometry aligned with the print. Review the metric thread, length, head diameter, head height, socket size, and key engagement before substituting another screw.

Technical Highlights

  • Head Style: Cylindrical socket head, internal hex drive
  • Material: 18-8 Stainless Steel
  • Thread Size: M3-0.5 (coarse metric pitch)
  • Length: 5 mm
  • Head Diameter: 5.50 / 5.20 mm (max/min)
  • Head Height: 3.00 / 2.86 mm (max/min)
  • Hex Key Size: 2.5 mm
  • Minimum Key Engagement: 1.3 mm
  • Dimensional Standard: ISO 4762 / DIN 912

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

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M3-0.5 x 6 18-8 Stainless Steel Metric Socket Head Cap Screw provides a cylindrical socket head and internal hex drive for metric assemblies exposed to ordinary moisture. The cylindrical socket head gives wrench access through the internal hex while keeping the head shape familiar for counterbored metric designs. Metric drawings from European suppliers may call this broad austenitic stainless family A2; do not treat that as a strength-grade claim.

Replacement repairs on humid plant equipment can use 18-8 stainless to reduce repeated rust-stain service issues. For stainless-on-stainless threads, moderate installation speed and a suitable lubricant or anti-seize help reduce galling risk.

Cold Headers has supplied specialty socket fasteners since 1962 and supports exact metric size identification. Review the metric thread, length, head diameter, head height, socket size, and key engagement before substituting another screw.

Technical Highlights

  • Head Style: Cylindrical socket head, internal hex drive
  • Material: 18-8 Stainless Steel
  • Thread Size: M3-0.5 (coarse metric pitch)
  • Length: 6 mm
  • Head Diameter: 5.50 / 5.20 mm (max/min)
  • Head Height: 3.00 / 2.86 mm (max/min)
  • Hex Key Size: 2.5 mm
  • Minimum Key Engagement: 1.3 mm
  • Dimensional Standard: ISO 4762 / DIN 912

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

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M3-0.5 x 8 18-8 Stainless Steel Metric Socket Head Cap Screw keeps the metric thread and length explicit for replacement work on stainless socket-head fastener locations. Head height in this socket head pattern corresponds to the nominal metric thread diameter, a useful check when reviewing counterbore clearance. For chloride, salt-spray, or marine-adjacent service beyond 18-8's comfort zone, a 316 stainless metric request can be quoted separately.

Common applications include food and beverage processing lines, guards, brackets, and washdown-adjacent machine panels.

Cut-to-length service can be reviewed for non-standard metric lengths when a catalog length does not match the drawing. Cold Headers can help identify hard-to-find metric stainless sizes while preserving the required thread and length. Review the metric thread, length, head diameter, head height, socket size, and key engagement before substituting another screw.

Technical Highlights

  • Head Style: Cylindrical socket head, internal hex drive
  • Material: 18-8 Stainless Steel
  • Thread Size: M3-0.5 (coarse metric pitch)
  • Length: 8 mm
  • Head Diameter: 5.50 / 5.20 mm (max/min)
  • Head Height: 3.00 / 2.86 mm (max/min)
  • Hex Key Size: 2.5 mm
  • Minimum Key Engagement: 1.3 mm
  • Dimensional Standard: ISO 4762 / DIN 912

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

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M3-0.5 x 10 18-8 Stainless Steel Metric Socket Head Cap Screw is selected when a metric print calls for stainless construction and ISO-style socket head geometry. Use the listed metric pitch and length directly when replacing hardware from a European or Asian machine print. For stainless-on-stainless assembly, run threads at moderate speed and use lubricant or anti-seize when galling is a concern.

Outdoor kiosks and enclosures can use 18-8 metric socket screws where weather exposure is present but 316 is not specified.

Review the metric thread, length, head diameter, head height, socket size, and key engagement before substituting another screw.

Technical Highlights

  • Head Style: Cylindrical socket head, internal hex drive
  • Material: 18-8 Stainless Steel
  • Thread Size: M3-0.5 (coarse metric pitch)
  • Length: 10 mm
  • Head Diameter: 5.50 / 5.20 mm (max/min)
  • Head Height: 3.00 / 2.86 mm (max/min)
  • Hex Key Size: 2.5 mm
  • Minimum Key Engagement: 1.3 mm
  • Dimensional Standard: ISO 4762 / DIN 912

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

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M3-0.5 x 12 18-8 Stainless Steel Metric Socket Head Cap Screw supports maintenance work where corroded plain steel hardware is being replaced with 18-8 stainless steel. The socket head form is common in machinery where strong tool engagement and compact radial clearance are needed. Where maximum clamp strength matters more than stainless corrosion performance, compare Alloy Steel Metric Socket Head Cap Screws.

Metric control enclosures and instrument housings use socket head fasteners where internal hex access is preferred. On many metric drawings, A2 stainless identifies the same broad chromium-nickel stainless family commonly called 18-8 in North America.

The catalog keeps this 18-8 metric SHCS family separate from alloy and inch-series socket head cap screws. Review the metric thread, length, head diameter, head height, socket size, and key engagement before substituting another screw.

Technical Highlights

  • Head Style: Cylindrical socket head, internal hex drive
  • Material: 18-8 Stainless Steel
  • Thread Size: M3-0.5 (coarse metric pitch)
  • Length: 12 mm
  • Head Diameter: 5.50 / 5.20 mm (max/min)
  • Head Height: 3.00 / 2.86 mm (max/min)
  • Hex Key Size: 2.5 mm
  • Minimum Key Engagement: 1.3 mm
  • Dimensional Standard: ISO 4762 / DIN 912

Call 773-775-7900 or email Sales@coldheaders.com for pricing, availability, or a quote.
Brands N/A Cold Headers, Inc.
Diameter N/A M3-0.5
Length N/A 5 mm N/A 6 mm N/A 8 mm N/A 10 mm N/A 12 mm
Material N/A 18-8 Stainless Steel
Quantity N/A 100
Package Type N/A Box
Note N/A Less Than Package Quantity Specified Plus 25%.