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Duplex Flat Bar

Duplex flat bar specifications

How does the performance of a Duplex Flat Bar in harsh environments?

These robust bars bring strength and corrosion resistance to construction, manufacturing, and fabrication. A duplex flat bar resists chloride stress-corrosion cracking and temperatures up to 1150°C. Its unique microstructure (50-50 austenite and ferrite stainless steel) lends it high yield strength and low thermal expansion.

An ASTM A276 UNS S31803 flat bar delivers sustainability in the automotive, engineering, and infrastructure sectors. However, 2507 (super duplex) is better than 2205 for offshore projects. More chromium, molybdenum, and nitrogen improve its corrosion resistance.

Inconel and titanium offer even higher resilience and strength than a duplex stainless steel flat bar. Titanium has advantages in durability due to its superior strength-to-weight ratio.

Duplex stainless steel flat bar stockists in Mumbai


Specification of duplex flat bar

Specifications Size Thickness
ASTM / ASME SA 276 / A 479 10 mm - 100 mm 4mm-100mm
Finish Hardness Cutting
Bright, polish & black HRB 62 - 180 - HV 140 - 1250 Plazma, machined cut
American standards Technique Processing service
AiSi, JIS, AISI, ASTM, GB, DIN, EN Hot rolled, polishing, cold rolled Bending, cutting, welding, punching, decoiling

We are UNS S31803 flat bars manufacturer in India, check sizes and dimension

Which standard bend test methods are used for a Duplex Flat Bar?

A DSS flat bar lets engineers work with lighter materials without impacting the structural performance. Duplex material is less susceptible to hot cracking after welding/bending than austenite grades. Even so, a free-formed or guided bend test detects possible defects (over 3mm length).

A duplex steel DIN 1.4462 flat bar can use transverse or longitudinal specimens for testing. Sometimes, a roller bend test is deemed more suitable.

Note that bend tests for UNS S31803 flat bars may not detect intermetallic phases and should coexist with more comprehensive procedures.

Applications of DSS flat bar


  • → Shipbuilding
  • → Defence
  • → Automotive
  • → Paper and pulp
  • → Fabrication
  • → Heavy earth moving equipment
  • → Construction
duplex flats

Types of duplex stainless steel flat bar


UNS 2205 flat bars

UNS 2205 flat bars

Duplex steel flat bar

Duplex steel flat bar

Duplex 2205 flat bars

Duplex 2205 flat bars

Dss flat bar

UNS S31803 flat bar

To assure their quality and performance, duplex steel DIN 1.4462 flat bars are put through a variety of quality control tests

How is the surface finish of Duplex Flat Bar checked and evaluated for quality and consistency?

Bright, polished, and black are standard surface finishes for these bars. Their smoothness and precision depend on the application, such as chemical processing, water treatment, or architecture. Client specifications dictate the surface roughness (Ra), the radius of curvature, and the effect of pickling and cold work on a UNS S32205 duplex steel flat bar.

We use contemporary surface-testing approaches, including electron microscopy, visual and tactile examination, and magnetic induction. We also assess the roughness parameters of ASME SA276 S31803 flat bars with a Fetoscope (to measure the ferrite content) or a gauge plunger.

The Mill Test Report details all the test results to assure clients of top-notch quality.

Chemical composition of UNS S31803 flat bar


Mo C Mn Cr Ni Si P S N Fe
3.00-3.50 .030 Max 2.00 Max 22.0-23.0 4.50-6.50 1.00 Max .030 Max .020 Max 0.14-0.20 Balance
To view the technical specifications of ASTM A276 UNS S32205 flat bar, visit us

Mechanical properties of duplex 2205 flat bar


Grade % Elongation YS (MPa) Hardness(BHN) UTS (MPa)
S31803 25 min. 450 min. 293 max. 620 min.
To read about the chemical and mechanical properties of ASME SA276 S31803 flat bars, refer to our technical data sheets

Equivalent grade of UNS S32205 flat bars


STANDARD WERKSTOFF NR. UNS
Duplex 1.4462 S31803 / S32205

Conditions of DSS flat bar


H&T Hardened and tempered.
PH Precipitation hardened.
ANN Annealed

Size chart of ASTM A276 UNS S31803 flat bar


Size (inch) Duplex flat bar sizes in mm Thickness (in Inches) Thickness (mm)
1 25 3/16 - 4/5 5 to 20
7/8 22 2/3 - 5/7 17 & 18
1-1/4 32 1/4 - 4/5 6 to 20
1-3/16 30 3/16 - 4/5 5 to 20
1-3/8 35 3/16 - 3/16 5 to 20
1-7/9 45 3/16 - 1 5 to 25
1-4/7 40 3/16 - 1 5 to 25
1-6/7 47 2/3, 1 & 1-1/4 17,25 & 32
2-1/16 55 3/16 - 1 5 to 25
2 50 3/16 - 1-1/4 5 to 32
2-1/4 57 1-1/4 32
2-1/2 63 3/8 - 1-3/16 10 to 30
2-3/8 60 3/16 - 1-3/8 5 to 35
2-5/9 65 3/8 - 1-3/16, & 1-3/8 10 to 30 & 35
3 75 5/16 - 1 8 to 25
2-3/4 70 1/4 - 1, & 1-4/7 6 to 25 & 40
3-1/8 80 5/16 - 4/5 8 to 20
4 100 5/16, 3/8, 1/2 8, 10, 12
3-1/2 90 5/16- 4/5 8 to 20

Tolerance of UNS S31803 flat bars


Type SIZES (Inches) SIZES (mm) ISO Tolerance
Cold drawn / ground flat bars 5/6" - 2.50" 10.00 - 75.00 h8-h9-h10-h11
Peeled / ground flat bars 3/4″ - 2.00" 20.00 - 50.00 h9-h10-h11
Cold drawn / polished flat bars 1/8" - 3.00" 3.00 - 75.00 h8-h9-h10-h11
Peeled / polished round bars 1.50" - 6.00" 40.00 - 150.00 h11, h11-DIN 1013

Applications of duplex stainless steel flat bar


  • Oil and gas
  • Nuclear and aerospace industries
  • Chemical processing
  • Transport and storage
  • Pharmaceutical
  • Sea Water
  • Petrochemical