18-8 Stainless Steel Metric Flat Head Socket Cap Screws

18-8 stainless steel metric flat head socket cap screws are precision threaded fasteners featuring a countersunk flat head and an internal hex drive for secure fastening in metric mechanical assemblies. When installed in a properly prepared countersunk hole, the head sits flush with the surrounding surface, making these fasteners well suited for applications where clearance, appearance, or moving components require a smooth finished profile. The internal hex drive allows installation where external wrench clearance is limited.

Manufactured from 18-8 stainless steel, these metric flat head socket cap screws provide general corrosion resistance for many industrial environments exposed to moisture, humidity, or routine washdown. They are commonly specified for metric machinery, automation equipment, robotics, instrumentation, electronic equipment, industrial enclosures, conveyors, maintenance repairs, and OEM manufacturing where stainless steel construction and flush-mounted fastening are required.

Proper fastener selection should consider metric thread size, screw length, countersink dimensions, nominal body diameter, head diameter, head height, metric 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 appropriate fastener.

Cold Headers supplies 18-8 stainless steel metric flat head socket 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 Flat Head Socket Cap Screws?

  • Countersunk flat head: Installs flush within a properly prepared countersunk hole.
  • Metric thread sizes: Designed for machinery and equipment utilizing metric fasteners.
  • 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 Flat Head Socket Cap Screw

Begin by confirming the required metric thread size and screw length. Review the countersink dimensions, body diameter, head diameter, head height, metric 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 flat head socket 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 Flat Head Socket Cap Screw
List Price (per 100 pieces) Call or Email for Pricing
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M3-0.5 x 6 18-8 Stainless Steel Metric Flat Head Socket Cap Screw
List Price (per 100 pieces) $9.15
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M3-0.5 x 8 18-8 Stainless Steel Metric Flat Head Socket Cap Screw
List Price (per 100 pieces) $9.20
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M3-0.5 x 10 18-8 Stainless Steel Metric Flat Head Socket Cap Screw
List Price (per 100 pieces) $9.25
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M3-0.5 x 12 18-8 Stainless Steel Metric Flat Head Socket Cap Screw
List Price (per 100 pieces) $9.30
Description N/A

M3-0.5 x 5 18-8 Stainless Steel Metric Flat Head Socket Cap Screw is a 90° countersunk 18-8 stainless steel metric flat head socket cap screw for flush seating in a matching metric countersink. The head is intended to seat flush when the mating countersink is correctly prepared for the metric flat-head angle.

Guide rails and slide tracks use metric flat heads where any projection can interrupt motion or rub against a moving part. Some metric drawings call this 18-8 family A2 stainless; that is material wording, not a mechanical rating. Confirm overall length, head diameter, head height, socket size, and key engagement before substitution.

Cold Headers has supported specialty socket fastener sourcing since 1962, including exact metric sizes for maintenance and production work. Cut-to-length service can be reviewed for non-standard metric lengths. Compare 18-8 Metric Socket Head Cap Screws when a full cylindrical head is preferred.

Technical Highlights

  • Head Style: Flat (countersunk), internal hex drive
  • Countersink Angle: 90°
  • Material: 18-8 Stainless Steel
  • Thread Size: M3-0.5 (coarse metric pitch)
  • Length: 5 mm (overall, including head)
  • Head Diameter: 6.00 / 5.82 mm (max/min)
  • Head Height: 1.86 mm (max)
  • Hex Key Size: 2.0 mm
  • Minimum Key Engagement: 1.05 mm
  • Dimensional Standard: ISO 10642

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 Flat Head Socket Cap Screw gives raised-head interference a cleaner answer: a metric flat head with internal hex drive access and 18-8 stainless construction. This geometry reduces surface projection so guides, tracks, and mating plates can pass over the fastened area more cleanly.

Food-equipment surfaces and wipedown panels often favor countersunk stainless screws because the finished face is easier to clean. Stainless-on-stainless threads can gall when driven fast and dry, so moderate installation speed with lubricant or anti-seize is common practice. Confirm overall length, head diameter, head height, socket size, and key engagement before substitution.

Cold Headers keeps this 18-8 metric flat head family separated from inch-series and alloy rows so purchasers can keep the drawing callout intact. 18-8 Metric Button Head Socket Cap Screws reduce projection without a countersink.

Technical Highlights

  • Head Style: Flat (countersunk), internal hex drive
  • Countersink Angle: 90°
  • Material: 18-8 Stainless Steel
  • Thread Size: M3-0.5 (coarse metric pitch)
  • Length: 6 mm (overall, including head)
  • Head Diameter: 6.00 / 5.82 mm (max/min)
  • Head Height: 1.86 mm (max)
  • Hex Key Size: 2.0 mm
  • Minimum Key Engagement: 1.05 mm
  • Dimensional Standard: ISO 10642

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 Flat Head Socket Cap Screw matches metric equipment drawings that call for ISO 10642 flat head geometry, a 90° countersink, and stainless material. The internal hex drive keeps installation access from the top face, which is useful where side wrench clearance is limited.

Washdown machinery panels, access covers, and stainless guards use these screws where metric drawings call for a flush fastener. Flat head screws measure length overall, including the head, so this size is selected by the total screw length shown on the print. Confirm overall length, head diameter, head height, socket size, and key engagement before substitution.

For machine repairs, Cold Headers can help match the thread, length, material, and countersunk geometry rather than substituting by appearance. Alloy Steel Metric Flat Head Socket Cap Screws serve alloy-material metric prints.

Technical Highlights

  • Head Style: Flat (countersunk), internal hex drive
  • Countersink Angle: 90°
  • Material: 18-8 Stainless Steel
  • Thread Size: M3-0.5 (coarse metric pitch)
  • Length: 8 mm (overall, including head)
  • Head Diameter: 6.00 / 5.82 mm (max/min)
  • Head Height: 1.86 mm (max)
  • Hex Key Size: 2.0 mm
  • Minimum Key Engagement: 1.05 mm
  • Dimensional Standard: ISO 10642

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 Flat Head Socket Cap Screw is used where a wipedown surface or sliding face needs the screw head seated into a prepared countersunk hole. Unlike a cylindrical socket head, the countersunk head spreads into the prepared recess instead of standing above the surface.

Packaging equipment can use metric flat head socket cap screws in wear strips, guards, brackets, and changeover components. Metric flat heads per ISO 10642 use a 90° countersink angle, while inch-series flat heads use 82°; the two styles do not seat properly in each other's countersinks. Confirm overall length, head diameter, head height, socket size, and key engagement before substitution.

Cold Headers supports distributors and MRO buyers who need stainless metric socket products identified by exact size. 18-8 inch-series Flat Head Socket Cap Screws belong with inch drawings.

Technical Highlights

  • Head Style: Flat (countersunk), internal hex drive
  • Countersink Angle: 90°
  • Material: 18-8 Stainless Steel
  • Thread Size: M3-0.5 (coarse metric pitch)
  • Length: 10 mm (overall, including head)
  • Head Diameter: 6.00 / 5.82 mm (max/min)
  • Head Height: 1.86 mm (max)
  • Hex Key Size: 2.0 mm
  • Minimum Key Engagement: 1.05 mm
  • Dimensional Standard: ISO 10642

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 Flat Head Socket Cap Screw keeps the metric diameter, pitch, and overall length explicit for stainless countersunk fastening work. The flush surface helps reduce snag points around covers, guards, slide paths, and handled equipment faces.

Stainless enclosures and covers use countersunk metric hardware where a smooth outside surface improves handling and appearance. Some metric drawings call this 18-8 family A2 stainless; that is material wording, not a mechanical rating. Confirm overall length, head diameter, head height, socket size, and key engagement before substitution.

When a metric length is hard-to-find, Cold Headers can help review the requirement without changing the material or head style. Left-hand threading can be quoted for special metric flat head applications.

Technical Highlights

  • Head Style: Flat (countersunk), internal hex drive
  • Countersink Angle: 90°
  • Material: 18-8 Stainless Steel
  • Thread Size: M3-0.5 (coarse metric pitch)
  • Length: 12 mm (overall, including head)
  • Head Diameter: 6.00 / 5.82 mm (max/min)
  • Head Height: 1.86 mm (max)
  • Hex Key Size: 2.0 mm
  • Minimum Key Engagement: 1.05 mm
  • Dimensional Standard: ISO 10642

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%.