317L Round Bar

Super Duplex Fasteners


ASTM A193 Duplex Steel Fasteners, Super Duplex Fasteners, Duplex Steel Industrial Fasteners, Super Duplex Bolts, Duplex Steel Washers, Super Duplex Anchor Fasteners, Duplex Steel Nuts, Super Duplex Screws, Duplex Steel Threaded Rods, Super Duplex Fasteners Manufacturer In World Wide

Super Duplex S32750 Heavy Hex Bolts, Duplex S32205 U Bolts, Super Duplex Stud Bolts, ASME SA194 Duplex Steel Fasteners Exporter, Duplex Metric Threaded Rods, Duplex S31803 Hex Nuts, Duplex Fasteners, Duplex 2205 Spring Washer, Duplex Wedge Type Anchor Bolts, Super Duplex S32760 Ogee Washers, Duplex Machine Screws, Super Duplex 2507 Socket Cap Screws, Duplex Steel Coupling Nuts, Super Duplex Fasteners Supplier In World Wide

Detailed Information:

As the largest manufacturer of Super Duplex Fasteners, RatnaExports.com (India) is the largest manufacturer of these Fasteners. The Super Duplex 2507 Bolts are available in four grades, including martensitic, austenitic, ferritic, and precipitation-hardened stainless steel. It is important to note that Super Duplex Screws contain a more significant amount of chromium than other steels and, as a result, are incredibly corrosion-resistant. It is steel made up of super duplex steel. It combines improved resistance to pitting, high strength, stress corrosion, crevice corrosion, and cracking with a high level of corrosion resistance. Super Duplex 2507 Stud Bolts contain approximately 24% chromium.

In addition to being resistant to stress corrosion caused by sulfides and chlorides, the Super Duplex Steel Nuts are also made of the super duplex steel. It has a maximum carbon range of 0.03% for ASTM A479 and UNS S32750 Stud Bolts. Grade 2507 fasteners are often replaced with Duplex Steel 2205 Fasteners in many applications. Despite their high mechanical strength and properties, Super Duplex Stud Bolts offer various design advantages. We manufacture different kinds of super duplex washers in India based on the physical properties of these properties that offer design advantages. It is known that Super Duplex 2507 Bolts are also known as UNS S32750 Bolts in the engineering and aerospace departments. X2CrNiMoN25 Bolts are steel with 25% chromium (25Cr Duplex), 4% molybdenum, and 7% nickel.

RatnaExports.com is a leading Super Duplex Fastener Manufacturer and manufactures fasteners in the 2507 duplex grade. The composition of the Super Duplex 2507 Fasteners gives the Super Duplex 2507 Fasteners their strength and corrosion resistance. The metallurgical microstructure of Super Duplex 2507 Bolts and other fasteners has austenitic and ferritic steel phases. It enables them to endure high corrosion without compromising high strength. ASTM SA790 specifies bolts and rivets to be used with UNS S32750.

This specification covers fasteners for high-temperature and pressure applications. They range in size from M02 to M30 and are available in various lengths ranging from 2mm to 200mm. This super duplex material has different grades, such as S31803, S32507, etc., which are determined by their compositional differences. These UNS S32760 Fg Stud Bolts and other fasteners also have high strength.

In terms of tensile strength, the Super Duplex Bolts and Nuts have a minimum tensile strength of 795MPa and a minimum yield strength of 550MPa. These values are almost twice those of the austenitic stainless steel grades. We manufacture the Super Duplex Hex Bolt and other fasteners in various sizes, shapes, and specifications as a leading manufacturer and supplier of these fasteners. For more information on the different types, including the Super Duplex Stainless Steel Bolt, and their prices, please contact us.

Super Duplex Fasteners Specification


2507 SS Fasteners Material Specification Super Duplex Nuts And Bolts, UNS S32750 Bolts
Standard DIN, UNI, ISO, JIS, GB, IS, BS, ASME, ANSI, ASTM, and all International Standards
2507 Stainless Steel Fasteners/ Bolts Size M2 Fasteners, M2.5 Fasteners, M3 Fasteners, M4 Fasteners, M5 Fasteners, M6 Fasteners, M8 Fasteners, M10 Fasteners, M12 Fasteners, M14 Fasteners, M16 Fasteners, M20 Fasteners, M24 Fasteners, M30 Fasteners, M36 Fasteners to M160 Fasteners
Length 3 mm to 200 mm
Super DSS Bolts, Studs Threads: METRIC, BSW, BSF, UNC, UNF or as required
2507 Fasteners Standard:

ANSI – American National Standards Institute

  • ANSI B 18.2.4 2M
  • ANSI B 28.2.4 1M
  • Super Duplex Stud Bolt lengths are defined in ASME B16.5 standard
  • Super Duplex Hex nuts are defined in ASME B18.2.2
  • ASME B18.5

DIN: DIN 931, DIN 933, DIN 934, DIN 970

UTS – Unified Thread Standard: UNC, UNF, UNEF, UNS, NPT, NPTF

ISO – International Organization for Standardization: ISO 4032, ISO 4033, JIS standards

Source of raw materials Tata Steel, JSPL, RINL, Usha Martin, Dhamm Steel, Mukund Steel, etc.
  • Hot Forged Super Duplex Fasteners, Nut / Bolt; up to M36 / 1-1/2” Dia, up to 1100mm lG
  • CNC Machined Super Duplex Fasteners, Nut / Bolt; up to M100 / 4” Dia, up to 1500mm lG
Super Duplex Fasteners In Form of Hex, Square, Round, Threading as per Gauge Etc.
Head drive: Phillips, Slotted, Phillips/Slot, Six-Lobe, etc.
Super Duplex bolting Test Certificate: Manufacturer Test Certificate as per EN 10204 / 3.1
Super Duplex Fasteners finishing:

Zinc (yellow, white, blue, black), black oxide,

Geometry, Dacroment, anodizing, nickel plated, plated zinc-nickel, Super Duplex: Passivated

Self-Colour, Hot Dip Galvanised (HDG), Bright Zinc Plated (BZP), Sherardized, Super duplex, Mechanically Applied coating and some special one like DACROMET.

Production process M2-M24: Cold Forging, hot forging M24-M100, machining, and CNC for Customised connecting element
Super Duplex bolting materials Surface Coating:
  • Teflon Coated Fasteners
  • Phosphate Coated Fasteners
  • Zinc Coated Fasteners
  • Ptfe Coated Super Duplex Fasteners
  • Xylan Coated Fasteners
  • Cadmium Coated Fasteners
  • Hot Dipped Galvanizing Coated Fasteners

All surface finishes offered including Geomet & PTFE, Galvanised, Zinc, Electroless Nickel, Sherardized, Dacromet

Popular Types of Super Duplex Stainless Steel Bolts 2507 Hex Bolts, 2507 Flange Bolts, 2507 Hex Head Bolts, 2507 Lag Bolts, 2507 Square Bolts, 2507 Eye Bolts, 2507 U Bolts, 2507 T Bolts, 2507 Countersunk Bolts, etc.
Popular Types of Super Duplex SS Nut 2507 Eye, 2507 Dome, 2507 Hex Head Nut, 2507 Panel, 2507 Lock, 2507 Coupling, 2507 Square, 2507 Acorn, 2507 T, 2507 Wing, etc.
Popular Types of 2507 Super Duplex Screw 2507 Socket Set Fasteners, 2507 Anchor Fasteners, 2507 Blind Rivet, 2507 Threaded Fasteners, 2507 Socket Head Fasteners, 2507 Machine Fasteners, 2507 Concrete Fasteners, 2507 Shoulder Fasteners, 2507 Panel Fasteners, 2507 Hex Head Cap Fasteners, etc.
Popular Types of Super Duplex 2507 Washers. ,2507 Machine Washers, 2507 Star Washers, 2507 Flat Washers, 2507 Lock Washers, 2507 Split Washers, 2507 Sealing Washers, etc.
Super Duplex Fasteners Packing: IN BULK: canton, pallet, Small Boxes/ carton/ pallet, or customer request


Chemical Composition of Super Duplex Fasteners


Content (%)

Chromium, Cr

24 – 26

Nickel, Ni

6 – 8

Molybdenum, Mo

3 – 5

Manganese, Mn

1.20 max

Silicon, Si

0.80 max

Copper, Cu

0.50 max

Nitrogen, N

0.24 – 0.32

Phosphorous, P

0.035 max

Carbon, C

0.030 max

Sulphur, S

0.020 max

Iron, Fe



Mechanical Properties of Super Duplex Steel Fasteners



Tensile Strength

(MPa) min

Yield Strength

0.2% Proof (MPa) min


(% in 50mm)


Rockwell C (HR C)

UNS-S 32750







Physical Properties of Super Duplex Fasteners


Properties Metric Imperial
Density 7.8 g/cm3 0.281 lb/in3
Melting point 1350°C 2460°F

The below table compares various metric sizes to the closest inch equivalent



Closest Inch


0-80 (Larger)


1-64 (Smaller)


3-56 (Larger)


4-48 (Smaller)


6-40 (Same)


8-36 (Larger)


10-32 (Smaller)


1/4-28 (Larger)


1/4-28 (Smaller)


5/16-18 (Smaller)


3/8-16 (Smaller)


1/2-13 (Larger)


9/16-12 (Larger)


5/8-11 (Smaller)


3/4-10 (Larger)


3/4-10 (Smaller)


7/8-9 (Larger)


1-8 (Larger)


1 1/8-7 (Smaller)


1 3/8-6 (Smaller)

Super Duplex Fasteners Grades


ASME B18.1.1 Small Solid Rivets ASME B18.8.1 Clevis Pins and Cotter Pins
ASME B18.1.2 Large Rivets ASME B18.8.2 Taper Pins, Dowel Pins, Straight Pins, Grooved Pins and Spring Pins
ASME B18.2.1 Square and Hex Bolts and Screws ASME B18.9 Plough Bolts
ASME B18.2.2 Square and Hex Nuts ASME B18.10 Track Bolts and Nuts
ASME B18.2.6 Fasteners for use in Structural Applications ASME B18.11 Miniature Screws
ASME B18.3 Socket Cap, Shoulder and Set Screws ASME B18.13 Screws and Washer Assemblies (Sems)
ASME B18.5 Round Head Bolts ASME B18.15 Forged Eye Bolts
ASME B18.6.2 Slotted Head Cap Screws, Square Head Set Screws, and Slotted Headless Set Screws ASME B18.17 Wing Nuts, Thumb Screws and Wing Screws
ASME B18.6.3 Machine Screws and Machine Screws Nuts ASME B18.21.1 Lock Washers
ASME B18.6.4 Thread Forming and Thread Cutting Tapping Screws and Metallic Drive Screws ASME B18.22.1 Plain Washers
ASME B18.7 General Purpose Semi- Tubular Rivets, Full Tubular Rivets, Split Rivets and Rivet Caps ASME B18.23.1 Bevelled Washers

Types Of Super Duplex Nuts :

    • Super Duplex Hex Nuts
    • Super Duplex Lock Nuts
    • Super Duplex Jam Nuts
    • Super Duplex Heavy Hex Nuts
    • Super Duplex Acorn Nuts
    • Super Duplex Flange Nuts
    • Super Duplex Slotted Nuts
    • Super Duplex Weld Nuts
    • Super Duplex Coupling Nuts
    • Super Duplex Wing Nuts
    • Super Duplex Square Nuts
    • Super Duplex Castle Nuts
    • Super Duplex Allenuts
    • Super Duplex Spring Nuts
    • Super Duplex Cage Nuts
    • Super Duplex High Nuts
    • Super Duplex Acme Nuts
    • Super Duplex Cap Nuts
    • Super Duplex Coil Nuts
    • Super Duplex Security Nuts
    • Super Duplex Handle Nuts
    • Super Duplex Hurricane Nuts
    • Super Duplex Hex Machine Screw Nuts
    • Super Duplex Self Clinching Nuts
    • Super Duplex Metric Nuts
    • Super Duplex Forged Eye Nuts
    • Super Duplex Rivet Nuts
    • Super Duplex Two-way reversible lock Nuts

Types Of Super Duplex Screws

    • Super Duplex Self Drilling Screw
    • Super Duplex Self Tapping Screw
    • Super Duplex Thread Rolling Screw
    • Super Duplex Thread Cutting Screw
    • Super Duplex Machine Screw
    • Super Duplex Concrete Screw
    • Super Duplex Roofing Screw
    • Super Duplex Drywall Screw
    • Super Duplex Particle Board Screw
    • Super Duplex Chipboard Screw
    • Super Duplex Construction screws
    • Super Duplex Coach screws / Lag Screw
    • Super Duplex Wood Screw
    • Super Duplex Euro Screw
    • Super Duplex Collated Screw
    • Super Duplex Furniture Screw
    • Super Duplex Sems Screw
    • Super Duplex Thumb & Wing Screws
    • Super Duplex Cap Screws
    • Super Duplex Phillips Head Screw
    • Super Duplex Set screws
    • Super Duplex Metric set screws
    • Super Duplex Sheet metal screws
    • Super Duplex Eye Screw

Application Of Super Duplex Bolts

  • Chemical process industries (heat exchangers and vessels).
  • Petrochemical industries (polymerization reactors and pipework)
  • Oil and gas industry.
  • Offshore platforms (heat exchangers, process and service water systems, fire-fighting systems, and injection and ballast water systems)
  • Fertilisers (Recirculation tanks, sedimentation tanks, phosphate reactor recirculation pumps)
  • Desalination plants (high-pressure RO-plant and seawater piping)
  • Mining/ Extraction (hot slurry pipe work, acid leach mining)
  • Engineering applications (pressure vessels)
  • Utility & industrial scrubber systems (absorber towers, ducting, piping)
  • Power industry FGD systems
  • Sewage (critically needed pipelines).

Countries We Export:

Afghanistan, Albania, Algeria, Andorra, Angola, Antigua-Barbuda Argentina, Armenia, Australia, Austria, Azerbaijan, Bahamas, Bahrain, Bangladesh, Barbados, Belarus, Belgium, Belize, Benin, Bhutan, Bolivia, Bosnia-Herzegovina, Botswana, Brazil, Brunei, Bulgaria, Burkina-Faso, Burundi, Côte d’Ivoire, Cabo Verde, Cambodia, Cameroon, Canada, Central African Republic, Chad, Chile, China, Colombia, Comoros, Congo (Congo-Brazzaville), Costa-Rica, Croatia, Cuba, Cyprus, Czechia (Czech Republic), Democratic Republic of the Congo, Denmark, Djibouti, Dominica, Dominican Republic, Ecuador, Egypt, El Salvador, Equatorial Guinea, Eritrea, Estonia, Eswatini (fmr. “Swaziland”), Ethiopia, Fiji, Finland, France, Gabon, Gambia, Georgia, Germany, Ghana, Greece, Grenada, Guatemala, Guinea, Guinea-Bissau, Guyana, Haiti, Holy See, Honduras, Hungary, Iceland, India, Indonesia, Iran, Iraq, Ireland, Israel, Italy, Jamaica, Japan, Jordan, Kazakhstan, Kenya, Kiribati, Kuwait, Kyrgyzstan, Laos, Latvia, Lebanon, Lesotho, Liberia, Libya, Liechtenstein, Lithuania, Luxembourg, Madagascar, Malawi, Malaysia, Maldives, Mali, Malta, Marshall Islands, Mauritania, Mauritius, Mexico, Micronesia, Moldova, Monaco, Mongolia, Montenegro, Morocco, Mozambique, Myanmar (formerly Burma), Namibia, Nauru, Nepal, Netherlands, New Zealand, Nicaragua, North Korea, North Macedonia, Norway, Oman, Pakistan, Palau, Palestine-State, Panama, Papua, New Guinea, Paraguay, Peru, Philippines, Poland, Portugal, Qatar, Romania, Russia, Rwanda, Saint Kitts and Nevis, Saint Lucia, Saint Vincent and the Grenadines, Samoa, San Marino, Sao Tome and Principe, Saudi Arabia, Senegal, Serbia, Seychelles, Sierra Leone, Singapore, Slovakia, Slovenia, Solomon Islands, Somalia, South Africa, South Korea, South Sudan, Spain, Sri Lanka, Sudan, Suriname, Sweden, Switzerland, Syria, Tajikistan, Tanzania, Thailand, Timor-Leste, Togo, Tonga, Trinidad and Tobago, Tunisia, Turkey, Turkmenistan, Tuvalu, Uganda, Ukraine, United Arab Emirates, United Kingdom, United States of America, Uruguay, Uzbekistan, Vanuatu, Venezuela, Vietnam, Yemen, Zambia, Zimbabwe.

Cities We Supply:

London, New-York, Paris, Moscow, Tokyo, Dubai, Singapore, Barcelona, Los-Angeles, Madrid Rome, Chicago, Toronto, San-Francisco, Abu-Dhabi, St-Petersburg, Amsterdam, Berlin Prague, Washington,Istanbul, Las-Vegas, Doha, Seoul, Sydney, Beijing,  Miami, Munich, Milan, San-Diego, Bangkok, Vienna, Dublin, Vancouver, Boston,  Zurich,  Melbourne, Budapest, Houston, Seattle, Montreal, Hong-Kong, Frankfurt, Sao-Paulo, Tel-Aviv, Copenhagen, Calgary, Orlando, Atlanta, Dallas, Hamburg, Osaka, Lisbon, Austin, Phoenix Naples, Oslo, Denver, Stockholm, Riyadh, Delhi, Buenos Aires, San-Jose, Brussels, Portland Philadelphia, Ottawa, Helsinki, Valencia, Brisbane, Warsaw, Minneapolis, Shanghai, Lyon, Adelaide, Edmonton, Marseille, Muscat, Athens, Stuttgart, Rio-De-Janeii, Baltimore, Auckland, Cologne, New-Orlean, Kuwait-City,  Kiev, Hanover, Perth, Minsk, Bucharest, Nashville, Dusseldorf, Manchester, Sacramento, Glasgow, Mexico-City, Salt-Lake-Ci, Raleigh, Cracow