Home » Hexagonal Stud Connector Nuts (DIN 6334) - Stainless Steel (A2)

Hexagonal Stud Connector Nuts (DIN 6334) - Stainless Steel (A2)

Hexagonal Stud Connector Nuts (DIN 6334) — Stainless Steel A2 (SUS304)

FULLERKREG DIN 6334 hexagonal long coupling nuts (also known as stud connector nuts, extension nuts, or long hex nuts) are precision-manufactured in A2 stainless steel (SUS304 / 1.4301) with a passivated (acid-washed) bright finish. Conforming to the DIN 6334 standard, the nut length is exactly 3 times the nominal thread diameter (3×d), providing the extended thread engagement needed to reliably join two threaded rods, studs, or bolts end-to-end. The passivated surface maximises corrosion resistance and delivers a clean, bright appearance. Available in thread sizes M3 through M56 for structural, mechanical, and architectural applications worldwide.

Dimensional Data

All dimensions in mm. Nut length m = 3×d (DIN 6334). Tolerances per ISO 4034 / DIN 6334. Unit weight (g) is theoretical reference value for SUS304 (density 7.93 g/cm³).

Thread
d		 Pitch
(mm)		 Nut Length
m = 3×d (mm)		 Across Flats
s (mm)		 Across Corners
e min (mm)		 Unit Weight
(g/pc)
M3 0.5 9.0 5.50 6.01 ~0.7
M4 0.7 12.0 7.00 7.66 ~1.6
M5 0.8 15.0 8.00 8.79 ~2.8
M6 1.0 18.0 10.00 11.05 ~5.0
M8 1.25 24.0 13.00 14.38 ~10.5
M10 1.5 30.0 16.00 17.77 ~19.5
M12 1.75 36.0 18.00 20.03 ~32.0
M14 2.0 42.0 22.00 24.49 ~55.0
M16 2.0 48.0 24.00 26.75 ~78.0
M18 2.5 54.0 27.00 29.56 ~108
M20 2.5 60.0 30.00 32.95 ~148
M22 2.5 66.0 32.00 35.03 ~185
M24 3.0 72.0 36.00 39.55 ~255
M27 3.0 81.0 41.00 45.20 ~380
M30 3.5 90.0 46.00 50.85 ~520
M33 3.5 99.0 50.00 55.37 ~680
M36 4.0 108.0 55.00 60.79 ~890
M39 4.0 117.0 60.00 66.44 ~1150
M42 4.5 126.0 65.00 71.30 ~1430
M45 4.5 135.0 70.00 76.95 ~1760
M48 5.0 144.0 75.00 82.60 ~2130
M52 5.0 156.0 80.00 88.25 ~2650
M56 5.5 168.0 85.00 93.56 ~3230

* Nut length m = 3×d per DIN 6334. Across Corners (e) calculated from s × 1.155. Unit weights are theoretical reference values; actual weights may vary ±5%. Sizes M39 and above may have longer lead times — please enquire.

Selection Guide

Parameter Specification
Standard DIN 6334
Also Known As Long Hex Nut, Coupling Nut, Extension Nut, Stud Connector Nut, Barrel Nut
Material Stainless Steel A2 (SUS304 / 1.4301)
Surface Treatment Acid-washed (Passivated / Bright Finish)
Nut Length 3×d (three times nominal thread diameter)
Thread Type Metric coarse thread (ISO 68-1)
Thread Tolerance 6H
Property Class A2-70 (per ISO 3506-2)
Thread Size Range M3 – M56
Tensile Strength ≥ 700 MPa
Hardness 147–220 HV
Operating Temperature -200°C to +300°C
Magnetic Non-magnetic (annealed condition)
RoHS Compliant Yes
Packaging Bulk bag / box; custom packaging available

Standard Notes

DIN 6334 specifies hexagonal long nuts with a length equal to 3 times the nominal thread diameter (m = 3×d). This extended length provides significantly greater thread engagement than a standard hex nut (typically 0.8×d), making DIN 6334 coupling nuts the correct choice for joining two externally threaded components — such as threaded rods, studs, or anchor bolts — end-to-end. The hexagonal profile allows standard spanners and sockets to be used for installation and removal.

  • DIN 6334 — Hexagon long nuts, metric coarse thread, length = 3×d
  • Equivalent / related standards: ISO 4033 (hex high nuts), EN 14399-3 (structural), ASME B18.2.2 (inch equivalent)
  • Material grade: A2 per ISO 3506-2 (SUS304 / 1.4301)
  • Surface: Passivated (acid-washed bright finish) — no additional coating
  • Thread: Right-hand, metric coarse, tolerance class 6H
  • Typical applications: Threaded rod extension, stud-to-stud connection, anchor bolt adjustment, height adjustment assemblies, furniture and architectural hardware

DIN 6334 vs Standard Hex Nut — Thread Engagement Comparison

Nut Type Standard Nut Length Thread Engagement Typical Use
Standard Hex Nut DIN 934 / ISO 4032 ~0.8×d Short Single bolt/stud fastening
High Hex Nut ISO 4033 ~0.9×d Medium Higher load single fastening
Long Coupling Nut DIN 6334 3×d Full engagement both ends Rod-to-rod / stud-to-stud joining ✓

Product Gallery

DIN 6334 Hexagonal Long Coupling Nuts — Stainless Steel A2 (SUS304) actual product photos:

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

Chemical Composition — A2 Stainless Steel (SUS304 / 1.4301)

Grade C (%) Si (%) Mn (%) P (%) S (%) Cr (%) Ni (%)
SUS304 (A2) ≤ 0.08 ≤ 1.00 ≤ 2.00 ≤ 0.045 ≤ 0.030 18.0–20.0 8.0–10.5

Mechanical Properties — A2-70 (ISO 3506-2)

Property Class Proof Load Stress (MPa) Tensile Strength (MPa) Hardness (HV) Min. Elongation
A2-70 ≥ 500 ≥ 700 147–220 ≥ 40%

Why Choose FULLERKREG DIN 6334 Coupling Nuts?

  • 🏭 Factory Direct — Manufactured in-house with full process control from raw material to finished part
  • 📐 Strict DIN 6334 Compliance — Length precisely 3×d; every dimension and tolerance verified against the standard
  • 🔗 Full Thread Engagement Both Ends — 3×d length ensures maximum load transfer when joining two threaded rods or studs
  • 🌊 Corrosion Resistant — A2 passivated finish provides reliable performance in atmospheric and mildly corrosive environments
  • 🔬 Material Certified — Mill test certificates (MTC) available; SUS304 composition verified by spectrometer
  • 📏 Wide Size Range — M3 through M56 in stock; covers the full range from precision instruments to heavy structural applications
  • 📦 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 lengths, and special requirements

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