Home » Full Thread Hex Bolts (DIN 933) - Duplex(2205) Stainless Steel

Full Thread Hex Bolts (DIN 933) - Duplex(2205) Stainless Steel

Full Thread Hex Bolts (DIN 933 / GB 5783) — Duplex 2205 Stainless Steel

FULLERKREG DIN 933 / GB 5783 full thread hex bolts in Duplex 2205 stainless steel (UNS S31803 / S32205) represent a step beyond conventional austenitic stainless steel fasteners. The duplex microstructure — a balanced combination of austenite and ferrite phases — delivers approximately twice the yield strength of standard 300-series stainless steel (A2/A4), combined with outstanding resistance to chloride stress corrosion cracking, pitting, and crevice corrosion. Finished with whitened passivation for maximum surface protection. Compliant with DIN 933, GB 5783, and ISO 4017 standards.

Product Highlights

  • Brand: FULLERKREG
  • Standards: DIN 933 / GB 5783 / ISO 4017
  • Material: Duplex 2205 Stainless Steel (UNS S31803 / S32205 / 1.4462)
  • Microstructure: Duplex (Austenite + Ferrite, approx. 50/50)
  • Thread Type: Full Thread (Fully Threaded Shank)
  • Surface Treatment: Whitened & Passivated (酸洗钝化)
  • Head Type: Hexagon (Hex Head)
  • Size Range: M6 – M36 (custom sizes available)
  • Thread: Metric coarse thread per ISO 261 / DIN 13
  • Key Advantage: ~2× yield strength of A2/A4 + superior stress corrosion cracking resistance

Why Choose FULLERKREG DIN 933 Duplex 2205 Hex Bolts?

  • ✅ Twice the yield strength of 300-series stainless — Yield strength ≥ 80 ksi (552 MPa) vs. ~210–450 MPa for A2/A4 grades
  • ✅ Superior chloride stress corrosion cracking (SCC) resistance — the critical failure mode of austenitic stainless in hot chloride environments
  • ✅ Excellent pitting & crevice corrosion resistance — PREN (Pitting Resistance Equivalent Number) ≥ 35, significantly higher than A4/316
  • ✅ High fatigue strength — duplex microstructure provides superior fatigue resistance under cyclic loading
  • ✅ Good sulfide stress corrosion resistance — suitable for sour gas and H₂S-containing environments
  • ✅ Low thermal expansion — approximately half that of austenitic stainless, reducing thermal stress in bolted joints
  • ✅ High energy absorption — excellent toughness for impact and dynamic load applications
  • ✅ Full thread design — maximum thread engagement; ideal for through-bolting and variable grip-length applications
  • ✅ Wholesale & bulk supply — available for offshore, chemical, and industrial distributors and OEMs

Duplex 2205 vs. Standard Stainless Steel — Performance Comparison

Property A2 (SUS304) A4 (SUS316) Duplex 2205 — This Product
Tensile Strength (UTS) ≥ 500–800 MPa ≥ 500–800 MPa ≥ 758–903 MPa (110–131 ksi) ✅
Yield Strength (0.2% offset) 210–600 MPa 210–600 MPa ≥ 483–669 MPa (70–97 ksi) ✅
Elongation 8–40% 8–40% 25% ✅
Molybdenum (Mo) None 2.0–2.5% 3.0–3.5% ✅
Chromium (Cr) 17–19.5% 16.5–18.5% 22.0–23.0% ✅
PREN (Pitting Resistance) ~18–20 ~24–26 ≥ 35 ✅
Chloride SCC Resistance Poor Moderate Excellent ✅
Sulfide SCC Resistance Poor Moderate Good ✅
Fatigue Strength Standard Standard Superior ✅
Thermal Expansion ~17 × 10⁻⁶/°C ~17 × 10⁻⁶/°C ~13 × 10⁻⁶/°C (lower) ✅
Microstructure Austenitic Austenitic Duplex (Austenite + Ferrite) ✅
Magnetic Non-magnetic Non-magnetic Slightly magnetic (ferrite phase)

Mechanical Properties — Duplex 2205 (Room Temperature)

Property Value
Ultimate Tensile Strength (UTS) 113–131 ksi (779–903 MPa) at room temperature
Yield Strength at 0.2% Offset 70–97 ksi (483–669 MPa) at room temperature
Elongation (%) 25%
Usable Temperature Limit 570°F / 300°C (continuous)
Hardness (typical) ≤ 310 HB / ≤ 32 HRC

Tensile Properties at Elevated Temperatures

Temperature (°F) Ultimate Tensile (ksi) Yield Strength at 0.2% Offset (ksi) Elongation (%)
Room Temp. 113–131 70–97 25
400 93–106 51–75 —
600 94 56 —
700 93 54 —

* Data from standard material specifications. Actual values may vary by heat and product form. For elevated temperature applications above 300°C (570°F), consult a materials engineer as duplex steels may experience embrittlement.

Chemical Composition — Duplex 2205 (UNS S31803 / S32205)

Element Fe Cr (%) Ni (%) Mo (%) Mn (%) Si (%) N (%) P (%) C (%) S (%)
Min % — 22.0 4.5 3.0 — — — — — —
Max % Bal. 23.0 6.5 3.5 2.0 1.0 0.2 0.030 0.03 0.02

Nitrogen (N) is a key alloying element in Duplex 2205, acting as a strong austenite stabilizer and significantly enhancing pitting corrosion resistance and strength. The high Chromium (22–23%) and Molybdenum (3.0–3.5%) content, combined with Nitrogen, gives Duplex 2205 its PREN ≥ 35 — far exceeding standard A4/316 stainless steel (PREN ~24–26).

Applicable Standards & Specifications

Standard Description
UNS S31803 / S32205 Duplex 2205 stainless steel — primary material designation
W. Nr. / EN 1.4462 European material number for Duplex 2205
Werkstoff 1.4462 Duplex German material designation
ASTM A 182 Forged or rolled alloy and stainless steel pipe flanges, fittings, and valves
ASTM A 240 Chromium and chromium-nickel stainless steel plate, sheet, and strip
ASTM A 276 Condition A / S Stainless steel bars and shapes
ASTM A 479 Stainless steel bars and shapes for use in boilers and pressure vessels
ASTM A 790 Seamless and welded ferritic/austenitic stainless steel pipe
ASME SA 182 / SA 240 / SA 479 / SA 789 ASME equivalents of ASTM standards
NACE MR0175 / ISO 15156 Sour service (H₂S) material requirements
NORSOK MDS D45 Grade F51 Norwegian offshore standard for Duplex 2205
DIN 933 / ISO 4017 / GB 5783 Full thread hexagon head bolt dimensional standard

Dimensional Specifications — DIN 933 / ISO 4017 Full Thread Hex Bolts

All dimensions in millimeters (mm). Data per DIN 933 / ISO 4017 standard.

Thread (d) Pitch (mm) s — A/F (mm) e — A/C (mm) k — Head Height (mm) d_w min (mm) Length Range (mm)
M6 1.0 10 11.05 4.0 8.9 10 – 80
M8 1.25 13 14.38 5.3 11.6 16 – 100
M10 1.5 17 18.90 6.4 14.6 20 – 120
M12 1.75 19 21.10 7.5 16.6 25 – 150
M16 2.0 24 26.75 10.0 22.5 35 – 200
M20 2.5 30 33.53 12.5 27.7 45 – 200
M24 3.0 36 39.98 15.0 33.3 50 – 200
M30 3.5 46 50.85 18.7 42.8 60 – 200
M36 4.0 55 60.79 22.5 51.1 70 – 200

* Custom sizes and lengths available on request. Contact FULLERKREG for non-standard requirements.

Application Scenarios

  • ⚓ Offshore & subsea oil and gas — platform structural connections, wellhead equipment, subsea manifolds in high-chloride, high-pressure environments
  • 🌊 Marine & shipbuilding — high-load structural bolting in seawater and salt-spray environments where SCC of austenitic stainless is a concern
  • 🧪 Chemical & petrochemical processing — chloride-containing process streams, acid environments, bleaching operations
  • 💧 Desalination plants — high-chloride brine environments where A4/316 suffers pitting failure
  • 💧 Pulp & paper industry — bleaching and washing equipment exposed to chlorine compounds
  • 🌡️ Sour gas & H₂S environments — NACE MR0175 / ISO 15156 compliant for sour service applications
  • 🏗️ Coastal & port infrastructure — high-load structural connections in aggressive marine atmospheres
  • ⚡ Offshore wind energy — monopile and jacket structure fastening in seawater splash zones
  • 🏭 Food processing — hygienic equipment in chloride-containing cleaning and processing environments
  • 💧 Water treatment & closed-loop systems — brackish water, cooling water, and process water systems

Product Gallery

FULLERKREG DIN 933 Full Thread Hex Bolts — Duplex 2205 Stainless Steel — actual product photos:

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

Ordering & Packaging Information

  • Packaging: Bulk carton / polybag per size and length; custom labeling available for OEM, offshore, and distributor orders
  • MOQ: Contact FULLERKREG sales for wholesale minimum order quantities
  • Lead Time: Duplex 2205 is a specialty material — lead times may be longer than standard stainless grades; contact us for current availability
  • Certifications: Material test reports (MTR), NACE MR0175 compliance documentation, and third-party inspection certificates available on request
  • Custom Requirements: Non-standard sizes, lengths, thread forms, and special markings available — contact us

Frequently Asked Questions

Q: What is Duplex 2205 stainless steel?
A: Duplex 2205 (UNS S31803 / S32205, EN 1.4462) is a two-phase stainless steel with a microstructure of approximately 50% austenite and 50% ferrite. This duplex structure provides approximately twice the yield strength of standard 300-series austenitic stainless steels (A2/A4), combined with superior resistance to chloride stress corrosion cracking, pitting, and crevice corrosion.

Q: Why choose Duplex 2205 over A4 (SUS316) stainless steel?
A: Duplex 2205 offers three key advantages over A4/316: (1) approximately twice the yield strength, allowing smaller bolt sizes for the same load; (2) far superior resistance to chloride stress corrosion cracking (SCC) — the primary failure mode of austenitic stainless in hot chloride environments; and (3) higher PREN (≥ 35 vs. ~24–26 for 316), meaning better pitting and crevice corrosion resistance.

Q: Is Duplex 2205 suitable for sour gas (H₂S) service?
A: Yes. Duplex 2205 meets NACE MR0175 / ISO 15156 requirements for sour service applications, making it suitable for oil and gas environments containing hydrogen sulfide (H₂S).

Q: What is the maximum service temperature for Duplex 2205?
A: The recommended maximum continuous service temperature is 300°C (570°F). Above this temperature, duplex steels may experience sigma phase embrittlement, which reduces toughness. For higher temperature applications, consult a materials engineer.

Q: Are Duplex 2205 bolts magnetic?
A: Yes, Duplex 2205 is slightly magnetic due to its ferrite phase content. This is a normal characteristic of duplex stainless steels and does not affect corrosion resistance or mechanical properties.

Q: What surface treatment is applied?
A: FULLERKREG Duplex 2205 hex bolts are acid-washed (whitened) and passivated, removing surface contamination and enhancing the natural chromium oxide passive layer for maximum corrosion resistance.

Q: Can I get material test reports (MTR) and NACE compliance documentation?
A: Yes. FULLERKREG provides full material test reports, chemical and mechanical property certifications, and NACE MR0175 / ISO 15156 compliance documentation upon request for wholesale and OEM orders.

FULLERKREG — Precision Fasteners to ISO/DIN/GB Standards. All technical data is provided for reference. Always verify fastener selection and torque requirements with a qualified engineer for structural and safety-critical applications.

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