Home » Weld Nuts (DIN 929) - Marine Stainless Steel (A4)

Weld Nuts (DIN 929) - Marine Stainless Steel (A4)

Weld Nuts (DIN 929) — Marine Stainless Steel A4 (SUS316)

FULLERKREG DIN 929 hexagon weld nuts in A4 marine-grade stainless steel (SUS316 / 1.4401) are engineered for demanding environments where superior corrosion resistance is critical. Manufactured to the DIN 929 standard, each nut features three symmetrically arranged welding projections on the bearing face that collapse and fuse with the base material during resistance welding, creating a flush, permanent, high-strength joint. The passivated (acid-washed) bright surface finish maximises corrosion resistance and ensures clean, oxide-free weld contact. Ideal for marine, offshore, chemical processing, food-grade, and coastal architectural applications. Available in thread sizes M3 through M16.

Dimensional Data

All dimensions in mm. Tolerances per DIN 929 / ISO 4042. Unit weight (g) is theoretical reference value for SUS316.

Thread
d		 Pitch
(mm)		 Nut Height
m (h14)		 Across Flats
s (h13)		 Across Corners
e (min)		 Spigot Dia.
d2 (tol d11)		 Spigot Proj.
h1 (tol)		 Weld Proj.
h2 (tol)		 Unit Weight
(g/pc)
M3 0.5 3.00 7.50 8.27 4.50 0.55 ±0.1 0.25 +0/-0.1 ~0.9
M4 0.7 3.50 9.00 9.91 6.00 0.65 ±0.1 0.35 +0/-0.1 ~1.6
M5 0.8 4.00 10.00 11.05 7.00 0.70 ±0.1 0.40 +0/-0.1 ~2.4
M6 1.0 5.00 11.00 12.12 8.00 0.75 ±0.15 0.50 +0/-0.1 ~3.9
M8 1.25 6.50 14.00 15.44 10.50 0.90 ±0.15 0.50 +0/-0.15 ~7.7
M10 1.5 8.00 17.00 18.72 12.50 1.15 ±0.2 0.65 +0/-0.15 ~14.6
M12 1.75 10.00 19.00 20.88 14.80 1.40 ±0.2 0.80 +0/-0.2 ~23.1
M14 2.0 10.00 19.00 20.88 14.80 1.40 ±0.2 1.00 +0/-0.2 ~25.5
M16 2.0 10.00 24.00 26.75 18.80 1.80 ±0.2 1.00 +0/-0.2 ~39.1

* Across Corners (e) calculated from s × 1.155. Unit weights are theoretical reference values for SUS316 (density 7.98 g/cm³); actual weights may vary ±5%. M14 has limited availability — higher MOQ applies.

Selection Guide

Parameter Specification
Standard DIN 929
Material Marine Stainless Steel A4 (SUS316 / 1.4401)
Surface Treatment Acid-washed (Passivated / Bright Finish)
Thread Type Metric coarse thread (ISO 68-1)
Thread Tolerance 6H
Nut Height Tolerance h14
Across Flats Tolerance h13
Spigot Diameter Tolerance d11
Welding Projections 3 projections, symmetrically arranged
Welding Method Resistance spot welding
Thread Size Range M3 – M16
Hardness ≤ 250 HV (A4 per ISO 3506-2)
Tensile Strength ≥ 500 MPa
Operating Temperature -200°C to +400°C
Pitting Resistance (PRE) ≥ 24 (Mo-bearing grade)
RoHS Compliant Yes
Packaging Bulk bag / box; custom packaging available

Standard Notes

DIN 929 specifies hexagon weld nuts with three welding projections on the bearing face. The spigot (pilot) locates the nut precisely on the workpiece prior to welding. Upon resistance welding, the projections collapse and fuse with the base material, creating a flush, permanent joint. The A4 (SUS316) grade adds 2–3% molybdenum to the A2 composition, significantly improving resistance to chloride-induced pitting and crevice corrosion — making it the preferred choice for marine, offshore, and chemical environments.

  • DIN 929 — Hexagon weld nuts, metric coarse thread
  • Equivalent standards: ISO 21670 (Type B, hexagonal), JIS B 1196
  • Material grade: A4 per ISO 3506-2 (SUS316 / 1.4401)
  • Surface: Passivated (acid-washed bright finish) — no additional coating
  • Thread: Right-hand, metric coarse, tolerance class 6H
  • Key advantage vs A2: Molybdenum addition provides superior chloride and pitting corrosion resistance

A4 vs A2 — When to Choose Marine Grade

Application Environment Recommended Grade
Indoor / dry / light corrosion A2 (SUS304)
Marine / coastal / saltwater exposure A4 (SUS316) ✓
Chemical processing / acids / chlorides A4 (SUS316) ✓
Food & beverage / pharmaceutical A4 (SUS316) ✓
Offshore / subsea structures A4 (SUS316) ✓
Swimming pools / desalination A4 (SUS316) ✓

Product Gallery

DIN 929 Hex Weld Nuts — Marine Stainless Steel A4 (SUS316) actual product photos:

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

Chemical Composition — A4 Marine Stainless Steel (SUS316 / 1.4401)

Grade C (%) Si (%) Mn (%) P (%) S (%) Cr (%) Ni (%) Mo (%)
SUS316 (A4) ≤ 0.08 ≤ 1.00 ≤ 2.00 ≤ 0.045 ≤ 0.030 16.0–18.0 10.0–14.0 2.0–3.0

* The molybdenum (Mo) content is the key differentiator from A2/SUS304, providing significantly enhanced resistance to pitting and crevice corrosion in chloride-containing environments.

Mechanical Properties — A4-70 (ISO 3506-2)

Property Class Proof Load Stress (MPa) Tensile Strength (MPa) Hardness (HV)
A4-70 ≥ 500 ≥ 700 147–220

Why Choose FULLERKREG DIN 929 Marine Weld Nuts?

  • 🏭 Factory Direct — Manufactured in-house with full process control from raw material to finished part
  • 🔬 Mo-Bearing Marine Grade — SUS316 with 2–3% Mo delivers superior chloride and pitting corrosion resistance vs standard A2
  • 📐 Strict DIN 929 Compliance — Every dimension and tolerance verified against the standard; no substitutions
  • 🔬 Material Certified — Mill test certificates (MTC) available; SUS316 composition verified by spectrometer
  • 🌊 Marine & Offshore Ready — Proven performance in saltwater, coastal, and chemical processing environments
  • ⚡ Weld-Ready Surface — Acid-washed bright passivated finish ensures clean weld contact; no oil or coating interference
  • 📦 Bulk Wholesale Supply — MOQ-friendly pricing tiers; consistent lot quality for production lines
  • 🚢 Global Export Experience — Shipped worldwide with proper export documentation and packaging
  • 💬 Technical Support — Engineering team available for application guidance, custom sizes, and special requirements

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