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A nickel-iron-chromium grade, RA330® offers an exceptional combination of strength and resistance to carburisation, oxidation and thermal shock.

RA330® was created to service the needs of the thermal process industries with a reliable source of a wrought product that could handle high temperature carburizing and nitriding conditions with repeated quenching. RA330® has excellent oxidation resistance up to 1148°C.


Product form Size range from Size range to
RA330® expanded metal To customer specifications To customer specifications
RA330® pipe 0.5 in 6 in
RA330® round bar 3.175 mm 152.4 mm
RA330® sheet & plate 1.22 mm 76.2 mm
RA330® welding wire 0.89 mm 3.175 mm
RA330® coil 1.22 mm 3.25 mm
RA330® pipe fittings 0.5 in 6 in

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    Sheet Coil

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    Expanded Metal

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    Round Bar

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    Sheet Metal

Chemical Analysis

% Cr Ni Si C Mn P S Cu Fe
Min 18 34 1 - - - - - Balance
Max 20 37 1.50 0.08 2 0.03 0.03 1 -


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Perfect for applications in the Thermal Processing industry

RA330® can be used in a variety of applications including:

  • Muffles and retorts
  • Quenching fixtures
  • Furnace, fans and shafts
  • Hot pressing platens
  • Bar baskets
  • Radiant tubes
  • Salt pots – both neutral and cyanite
  • Tube hangers for crude oil heaters and steam boilers

About RA330®

The chemical composition of RA330® has changed over the years to allow for improved performance in the thermal process industry.

RA330® is the workhorse of the heat resistant alloys with good strength and oxidising resistance up to 1148°C. In addition, the alloy is excellent in carburising and nitriding environments.

The properties of RA330® are enhanced by a nominal 1.25% silicon addition. It has been designed to withstand thermal shock induced by liquid quenching.

RA330® finds wide applications in high temperature environments where good resistance to the combined effect of carburisation and thermal cycling conditions are the prime requisite.

RA330® remains fully austenitic at all temperatures so it is not subject to sigma embrittlement. It is highly resistant to chloride-induced stress corrosion cracking and thus an alloy of choice where common stainless grades have failed by stress corrosion cracking.

RA330® can be fabricated and machined using procedures used for stainless steels or nickel-chromium alloys. Heat treatment is not necessary after most forming and welding operations. When required, the recommended full anneal is 1038-1371°C, rapid air cool or water quench. RA330® can be readily welded using RA330-04® or other weld fillers of matching conditions.

RA330® is the registered trademark of Rolled Alloys Inc.


7944 g/cm³


UNS Number:
Werkstoff Number:
ASTM B511, B512, B535, B536, B546, B710, B739, AMS 5592, 5716, B829, B726
Download the RA330® Data Sheet Download

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