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Non-Standards Are Our Standard

Super Duplex Bolts and Fasteners Manufacturer

Here at Smith Bullough, we offer Super Duplex stainless steel bolts and fasteners with short production lead times.

What is Super Duplex Stainless Steel?

Super Duplex stainless steel is a combined microstructure comprising a 50:50 ration of ferrite and austenite. Duplex alloy already demonstrates a significant improvement over regular austenitic and ferritic steel grades. Super Duplex takes things further with an increased chromium and molybdenum content. This makes the resultant steel far more hard-wearing, with increased ductility and stress corrosion resistance.

Properties of Super Duplex Stainless Steel

Super Duplex stainless steel is available in several grades. At Smith Bullough, we use UNS 32750 and UNS 32760 Super Duplex in the manufacture of our bolts and fasteners.

Both variations offer greater corrosion resistance compared to Duplex, as well as greater tensile strength and yield strength. Both offer good toughness and ductility, in addition to good resistance to stress corrosion cracking. They are both cost-effective materials for any company looking to reduce material costs without compromising on component quality.

UNS 32760 Super Duplex contains a slightly higher proportion of copper and tungsten, compared with UNS 32750. This gives the material an even greater resistance to inorganic acids, such as sulphuric and hydrochloric acid.

Super Duplex32750, 32760UNS 32750, 32760

Types of Super Duplex Bolts & Fasteners

Smith Bullough manufactures a wide variety of Super Duplex fasteners and bolts on site. Whatever your particular requirements might be, we will have the appropriate solution. These include:

  • Hexagon bolts and set screws
  • Stud bolts
  • Engineer studs
  • Socket cap screws
  • Socket set screws
  • Socket countersunk screws
  • Nuts
  • Washers
  • Machined parts
  • Specials to drawing


Due to superior corrosion resistance, Super Duplex fasteners and bolts are used across a wide array of industries. This material is particularly popular in sectors that utilise large volumes and concentrations of water and corrosive chemicals. Super Duplex fasteners are in regular use within the following industries:

  • marine construction
  • ship building
  • chemical plants
  • water desalination plants
  • pulp and paper processing plants
  • petrochemical and pollution control sectors
  • recycling centres


Super Duplex fasteners are extremely versatile and have many useful applications:

  • oil and gas components
  • hot water tanks
  • manifolds
  • heat exchangers
  • connectors
  • water heaters
  • pipework and flanges
  • compressor and pump components
  • pumps, valves, and chokes

Contact The Experts

For more information or to discuss an order, contact Smith Bullough today.

Call us on 01942 520 250 for a free, no-obligation quotation.

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