Home » DIN 6798A-A2 Stainless External Serrated

DIN 6798A-A2 Stainless External Serrated

DIN 6798A External Serrated Lock Washer — A2 Stainless Steel (SUS304), Whitened & Passivated

FULLERKREG DIN 6798A external serrated lock washers are manufactured to DIN 6798 Form A standard in A2 stainless steel (SUS304 / 1.4301 / 0Cr18Ni9) with a whitened and passivated surface finish. DIN 6798 Form A features external serrations (teeth on the outer diameter) that bite into the substrate surface under the bolt head or nut, providing positive anti-loosening performance through mechanical engagement. The external serration design maximizes the contact area between the washer and the substrate, making it the most widely used serrated lock washer type for general industrial applications. A2 stainless steel provides excellent general corrosion resistance, non-magnetic properties, and food-safe compliance.

Product Highlights

  • Standard: DIN 6798 Form A (External Serrated Lock Washer)
  • Material: A2 Stainless Steel (SUS304 / 1.4301 / 0Cr18Ni9)
  • Surface Treatment: Whitened & Passivated
  • Size Range: M3 – M30
  • Serration type: External (teeth on outer diameter — bite into substrate surface)
  • Anti-loosening mechanism: Mechanical tooth engagement — resists rotation under vibration
  • Maximum contact area — larger effective tooth radius vs. internal serrated
  • Non-magnetic, non-sparking
  • RoHS & REACH Compliant

Dimensional Specifications — DIN 6798 Form A (External Serrated), A2 Stainless

All dimensions in millimeters (mm). Per DIN 6798 Form A.

For Thread Nominal Size d1 min d1 max d2 Nominal d3 approx. Min. No. of Teeth s min s max kg/1000pcs
M3 3 3.2 3.5 6.5 5.3 9 0.3 0.4 0.025
M3.5 3.5 3.7 4.0 7.5 6.0 9 0.3 0.4 0.04
M4 4 4.3 4.6 8.0 6.5 11 0.4 0.5 0.06
M5 5 5.3 5.6 9.5 7.7 11 0.5 0.6 0.1
M6 6 6.4 6.8 11.5 9.3 14 0.5 0.6 0.17
M7 7 7.4 7.8 13.0 10.5 14 0.5 0.6 0.24
M8 8 8.4 8.8 15.0 12.1 14 0.6 0.8 0.38
M10 10 10.5 11.0 18.0 14.6 16 0.8 1.0 0.7
M12 12 13.0 13.5 21.0 17.0 18 0.8 1.0 0.9
M14 14 15.0 15.5 24.0 19.5 18 0.8 1.0 1.2
M16 16 17.0 17.5 27.0 21.9 18 1.0 1.2 1.9
M18 18 19.0 19.5 30.0 24.4 18 1.0 1.2 2.3
M20 20 21.0 21.5 33.0 26.8 20 1.0 1.2 3.0
M22 22 23.0 23.5 36.0 29.3 20 1.0 1.2 3.7
M24 24 25.0 25.5 39.0 31.7 20 1.2 1.5 5.5
M27 27 28.0 28.5 44.0 35.8 20 1.2 1.5 7.0
M30 30 31.0 31.5 47.0 38.2 20 1.2 1.5 8.0

All dimensions in mm per DIN 6798 Form A. d1 = inner diameter; d2 = outer diameter; d3 = serration root diameter; s = thickness.

DIN 6798 Form A vs. Form J vs. Form V — Key Differences

Feature Form A (External) Form J (Internal) Form V (Countersunk)
Serration location Outer diameter Inner diameter Outer diameter, countersunk
Bites into Substrate surface Fastener shank / bolt Substrate surface (countersunk)
Outer surface Marked by teeth Preserved — no marking Flush with surface
Contact area Maximum — larger tooth radius Standard Standard
Typical use General anti-loosening, most common type Where outer appearance must be preserved Countersunk screw assemblies

Material & Mechanical Properties — A2 Stainless Steel (SUS304)

Property Value
Material Grade A2 / SUS304 / 1.4301 / 0Cr18Ni9
Cr Content 17.5 – 19.5%
Ni Content 8.0 – 10.5%
Surface Treatment Whitened & Passivated
Magnetic Non-magnetic (austenitic)
Operating Temperature -196°C to +300°C
Corrosion Resistance Excellent — atmospheric, fresh water, mild chemicals
RoHS / REACH Compliant

How External Serrated Lock Washers Work

  • External serrations: Sharp teeth on the outer diameter bite into the substrate surface (under bolt head or nut) as the fastener is tightened
  • Mechanical engagement: The teeth create a positive mechanical lock that resists rotation under vibration and dynamic loads
  • Maximum torque resistance: External teeth act at the largest possible radius, maximizing the anti-loosening torque compared to internal serrations
  • Most common type: Form A is the standard general-purpose serrated lock washer for industrial applications

Application Scenarios

  • General industrial bolted assemblies — most widely used serrated lock washer type
  • Food & beverage processing equipment — A2 stainless, food-safe, easy to clean
  • Medical & pharmaceutical equipment — non-magnetic, corrosion-free
  • Electronics & electrical enclosures — non-magnetic, reliable anti-loosening
  • Outdoor & architectural hardware — excellent atmospheric corrosion resistance
  • Automotive & transportation — vibration resistance in corrosive environments
  • HVAC & mechanical systems — reliable fastening in humid environments

Product Photo Gallery

FULLERKREG DIN 6798A External Serrated Lock Washer, A2 Stainless Steel:

[ Photo 1 ] [ Photo 2 ] [ Photo 3 ] [ Photo 4 ]

Why Choose FULLERKREG?

  • 🏭 Direct manufacturer — factory in China, no middlemen
  • 📐 Strict DIN dimensional control — 100% inspection on critical dimensions
  • 🌍 Global export experience — serving distributors in Europe, North America, Southeast Asia
  • 📦 Flexible MOQ — small trial orders and large bulk shipments both welcome
  • 📋 Full documentation — material certs, RoHS declarations, test reports available
  • ⚡ Fast lead times — standard sizes in stock, ready to ship

Frequently Asked Questions

Q: What is DIN 6798 Form A?
A: DIN 6798 Form A is an external serrated lock washer. The serrations (teeth) are on the outer diameter and bite into the substrate surface under the bolt head or nut when tightened, providing mechanical anti-loosening. It is the most common type of serrated lock washer for general industrial use.

Q: What is the difference between Form A (external) and Form J (internal)?
A: Form A has teeth on the outer diameter — they bite into the substrate surface, maximizing anti-loosening torque. Form J has teeth on the inner diameter — they bite into the fastener shank, preserving the outer substrate surface. Choose Form A for maximum anti-loosening performance; choose Form J when the outer appearance must be preserved.

Q: Is A2 stainless steel food-safe?
A: Yes. A2 (SUS304) is widely used in food processing and pharmaceutical equipment. Non-toxic, easy to clean, resistant to most food-contact environments.

Q: Do you provide material test certificates?
A: Yes. Mill certificates, chemical composition reports, and dimensional inspection reports are available upon request.

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