M5X8mm – 316 – Stainless Steel – Serrated – Hexagon flange bolt

¥0.386 - ¥1.015
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M5X10mm – 316 – Stainless Steel – Serrated – Hexagon flange bolt

¥0.410 - ¥1.080
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M5X12mm – 316 – Stainless Steel – Serrated – Hexagon flange bolt

¥0.414 - ¥1.090
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M5X16mm – 316 – Stainless Steel – Serrated – Hexagon flange bolt

¥0.471 - ¥1.240
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M5X20mm – 316 – Stainless Steel – Serrated – Hexagon flange bolt

¥0.511 - ¥1.345
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M5X25mm – 316 – Stainless Steel – Serrated – Hexagon flange bolt

¥0.578 - ¥1.520
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M5X30mm – 316 – Stainless Steel – Serrated – Hexagon flange bolt

¥0.640 - ¥1.685
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M5X35mm – 316 – Stainless Steel – Serrated – Hexagon flange bolt

¥0.737 - ¥1.940
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M5X40mm – 316 – Stainless Steel – Serrated – Hexagon flange bolt

¥0.794 - ¥2.090
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M6X8mm – 316 – Stainless Steel – Serrated – Hexagon flange bolt

¥0.589 - ¥1.550
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M6X10mm – 316 – Stainless Steel – Serrated – Hexagon flange bolt

¥0.688 - ¥1.810
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M6X12mm – 316 – Stainless Steel – Serrated – Hexagon flange bolt

¥0.646 - ¥1.700
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M6X16mm – 316 – Stainless Steel – Serrated – Hexagon flange bolt

¥0.713 - ¥1.875
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M6X20mm – 316 – Stainless Steel – Serrated – Hexagon flange bolt

¥0.771 - ¥2.030
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M6X25mm – 316 – Stainless Steel – Serrated – Hexagon flange bolt

¥0.846 - ¥2.225
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M6X30mm – 316 – Stainless Steel – Serrated – Hexagon flange bolt

¥0.923 - ¥2.430
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M6X35mm – 316 – Stainless Steel – Serrated – Hexagon flange bolt

¥1.040 - ¥2.738
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M8X12mm – 316 – Stainless Steel – Serrated – Hexagon flange bolt

¥1.264 - ¥3.325
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M8X16mm – 316 – Stainless Steel – Serrated – Hexagon flange bolt

¥1.221 - ¥3.213
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M8X20mm – 316 – Stainless Steel – Serrated – Hexagon flange bolt

¥1.325 - ¥3.488
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M8X25mm – 316 – Stainless Steel – Serrated – Hexagon flange bolt

¥1.482 - ¥3.900
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M8X30mm – 316 – Stainless Steel – Serrated – Hexagon flange bolt

¥1.610 - ¥4.238
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M8X35mm – 316 – Stainless Steel – Serrated – Hexagon flange bolt

¥1.701 - ¥4.475
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M8X40mm – 316 – Stainless Steel – Serrated – Hexagon flange bolt

¥1.834 - ¥4.825
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Technical Superiority of Grade 316 (A4)

Grade 316 is often referred to as "acid-proof" or "marine-grade" steel. While it looks identical to Grade 304, its internal chemistry is different. The addition of Molybdenum gives it a specific resistance to chloride corrosion (salt), making it the mandatory choice for coastal projects. When combined with a serrated flange, it offers a dual benefit: chemical durability and mechanical security.

Material Specifications and Grades

Our 316 serrated flange bolts are typically supplied in accordance with ISO 3506 standards:
Feature Specification Benefit
Designation A4 (Austenitic Group 4) The highest corrosion resistance class for standard metric fasteners.
Key Element Molybdenum (2-3%) Prevents "pitting" corrosion commonly caused by salt spray and chlorides.
Strength Class A4-70 (Standard) Tensile Strength: 700 N/mm². Provides structural reliability similar to high-tensile carbon steel.

Quality Assurance

Material verification is critical when paying for premium alloys. An EN 10204 3.1 Material Certificate confirming the Molybdenum content is available upon request. Please note that third-party inspection services require an additional fee.

Critical Applications for SS316

These bolts are designed for environments that would rapidly destroy standard steel or Grade 304 fasteners:
  • Marine Industry: Deck fittings, engine mounts, and hull components on boats and ships.
  • Chemical Processing: Flange connections in pipelines carrying aggressive fluids or gases.
  • Coastal Construction: Outdoor structures, balustrades, and solar arrays located within 5km of the ocean.
  • Medical & Pharmaceutical: Equipment requiring sterile, non-reactive, and cleanable surfaces.

Frequently Asked Questions

What is the difference between A2 and A4 stainless steel?

A2 is Grade 304, and A4 is Grade 316. The main difference is Molybdenum. A4 (316) contains Molybdenum, which makes it resistant to salt water and industrial chemicals. A2 (304) does not have this element and will eventually corrode or stain if exposed to sea water.

How do I prevent galling on 316 bolts?

Grade 316 bolts are prone to "galling" (thread seizing) because the metal is tough and ductile. To prevent this, especially with serrated flange bolts that require high torque, you must use an anti-seize lubricant (like nickel or molybdenum disulfide paste) on the threads and tighten them slowly.

Can I use serrated flange bolts on painted surfaces?

The serrations are designed to cut into the surface to lock the bolt. If you use them on a painted marine surface, the serrations will break the paint seal, potentially allowing rust to form on the base metal underneath. In these cases, you might consider using a smooth flange bolt with a separate sealing washer, or ensure the base metal is also corrosion-resistant.