Home » DIN 6798J-A2 Stainless Internal Serrated

DIN 6798J-A2 Stainless Internal Serrated

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

FULLERKREG DIN 6798J internal serrated lock washers are manufactured to DIN 6798 Form J standard in A2 stainless steel (SUS304 / 1.4301 / 0Cr18Ni9) with a whitened and passivated surface finish. DIN 6798 Form J features internal serrations (teeth on the inner diameter) that bite into the fastener shank or bolt head bearing surface, providing positive anti-loosening performance through mechanical engagement. The internal serration design protects the outer surface of the assembly — ideal for applications where the outer appearance must be preserved. A2 stainless steel provides excellent general corrosion resistance, non-magnetic properties, and food-safe compliance.

Product Highlights

  • Standard: DIN 6798 Form J (Internal Serrated Lock Washer)
  • Material: A2 Stainless Steel (SUS304 / 1.4301 / 0Cr18Ni9)
  • Surface Treatment: Whitened & Passivated
  • Size Range: M3 – M30
  • Serration type: Internal (teeth on inner diameter — bite into fastener shank)
  • Anti-loosening mechanism: Mechanical tooth engagement — resists rotation under vibration
  • Outer surface preserved — no marking on substrate outer surface
  • Non-magnetic, non-sparking
  • RoHS & REACH Compliant

Dimensional Specifications — DIN 6798 Form J (Internal Serrated), A2 Stainless

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

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 J. d1 = inner diameter; d2 = outer diameter; d3 = serration root diameter; s = thickness.

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

Feature Form J (Internal) Form A (External) Form V (Countersunk)
Serration location Inner diameter Outer diameter Outer diameter, countersunk
Bites into Fastener shank / bolt Substrate surface Substrate surface (countersunk)
Outer surface Preserved — no marking Marked by teeth Flush with surface
Typical use Where outer appearance must be preserved General anti-loosening 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 Internal Serrated Lock Washers Work

  • Internal serrations: Sharp teeth on the inner diameter bite into the fastener shank or the underside of the bolt head as the fastener is tightened
  • Mechanical engagement: The teeth create a positive mechanical lock that resists rotation under vibration and dynamic loads
  • Outer surface preserved: Because the teeth are on the inner diameter, the outer surface of the substrate is not marked — ideal for visible or finished surfaces
  • Higher tooth count: Internal serrations typically have more teeth per unit circumference than external serrations, providing finer engagement

Application Scenarios

  • Visible or finished surfaces — internal teeth preserve outer substrate appearance
  • 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
  • Marine & coastal installations — A2 stainless for general corrosion protection

Product Photo Gallery

FULLERKREG DIN 6798J Internal 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 J?
A: DIN 6798 Form J is an internal serrated lock washer. The serrations (teeth) are on the inner diameter and bite into the fastener shank or bolt head underside when tightened, providing mechanical anti-loosening without marking the outer substrate surface.

Q: What is the difference between Form J (internal) and Form A (external)?
A: Form J has teeth on the inner diameter — they bite into the fastener, preserving the outer substrate surface. Form A has teeth on the outer diameter — they bite into the substrate surface. Choose Form J when the outer appearance of the assembly 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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