A shaft carries torque and bending, it fatigues, and it usually does all of that immersed in whatever the machine is moving. That combination is why grade selection for shafting is unforgiving.

We supply the bar that shafts are machined from, across the super duplex, austenitic, nickel and copper ranges, from stock in the UK and USA.

Why is super duplex the default for pump shafts?

A shaft has to meet three requirements at once: high yield strength, a PREN above 40 for chloride resistance, and good wear and erosion resistance. Super duplex meets all three in one grade. Alloy 32750 and Alloy 32760 are widely specified, with Ferralium® 255 preferred in larger sections.

Ferralium® 255 or Alloy 32750 for a large-diameter shaft?

Ferralium® 255 for large sections: sigma phase, which embrittles super duplex in thick sections, is less likely in Ferralium® 255, and its minimum proof stress is higher. For smaller diameters both perform well and availability often decides.

Which alloy for a non-magnetic shaft?

Fermonic® 50 - a nitrogen-strengthened austenitic that stays fully austenitic, and so fully non-magnetic, even after severe cold working, while keeping toughness at low temperatures.

Which alloy for sour-service shafts?

Alloy 718 and Alloy 725 for high strength to NACE MR0175 and ISO 15156, with Alloy 925 where cost and strength need balancing.

Which alloy for a seawater lift or firewater pump shaft?

Super duplex for the wetted parts, with Hiduron® 130 where the pump sits idle between duty cycles - its anti-fouling behaviour and crevice resistance mean it restarts reliably after inactivity.

Which alloy for marine propeller shafts?

Alloy K-500 (nickel-copper) and the high-strength cupronickels for seawater strength and corrosion resistance.

Also known as

Alloy 32760 is equivalent to UNS S32760, also known as Zeron 100®, a trademark of Rolled Alloys. Alloy 32750 is equivalent to UNS S32750, also known as SAF 2507®, a trademark of Alleima. Ferralium® 255 is the Langley Alloys trade name for UNS S32550. Fermonic® 50 is our designation for UNS S20910, known elsewhere as Nitronic® 50, a trademark of Cleveland-Cliffs (formerly AK Steel). Alloy 718 and Alloy 725 are equivalent to UNS N07718 and N07725, sold elsewhere as Inconel® 718 and Inconel 725, trademarks of Special Metals. Alloy K-500 is equivalent to UNS N05500, sold elsewhere as Monel® K-500, a trademark of Special Metals. Hiduron® 130 meets DIN 2.1504 and DTD 900/4805 (also designated UNS C72400). 17-4 PH is UNS S17400 (AISI 630).

Typical shaft work

Pump shafts and sleeves, propeller and propulsion shafts, drive and line shafts, spindles.

Why buy from us

  • Bar in large diameters, so long shafts come from one piece - send us the size and we will confirm from current stock.
  • Alloy 316L hollow bar for sleeves and spacers, removing a boring operation.
  • Sawing and cut-to-length, with grade selection and equivalents support.

We supply the bar that shafts are machined from.

Related sectors: marine and offshore, oil and gas, and desalination. Related applications: pumps, valves and marine propulsion. See also our material calculators.