Home / Resources / Product Information / Stainless Grades / 300 Series / 330 Stainless Steel

330 Stainless Steel

Penn Stainless inventory now includes 330 stainless steel Plate and Processed Flat Bar (Alloy 330 UNS N08330), ideally suited for demanding, high-temperature, high-pressure applications such as chemical and petrochemical processing, thermal processing, ore processing, and power generation.


General Properties

Alloy 330 is an austenitic, nickel-chromium-iron-silicon alloy that has outstanding resistance to oxidation and carburization up to 2200°F with high strength. The excellent resistance to oxidation and carburization is provided by the high nickel and chromium content of the alloy, further enhanced by its silicon content. Alloy 330’s ultra high nickel content of 34 to 37% also provides high resistance to chloride stress corrosion cracking and embrittlement from the precipitation of sigma phase in most furnace atmospheres. Alloy 330 also has a low coefficient of expansion, excellent ductility, and high strength.


Alloy 330 is extensively used in high temperature environments where resistance to the combined effects of thermal cycling and carburization is necessary. Applications include:

  • Chemical and Petrochemical Processing: cracked ammonia components, petrochemical furnace parts, heat exchangers, flares, etc
  • Thermal Processing: heat-treat furnace containers & compartments, high temperature fans, salt pots, etc
  • Ore Processing: perlite system and equipment
  • Power Generation: boiler fixtures, gas turbine components, etc

Value Added Services:

  • Need a special length?
    • We can custom level 3/8″ thick x 72″ x 186″ from our plate line to reduce scrap
  • Polish plate inventory available
    • We supply #4, #6, and #8 mirror finish
    • Special polishes available
  • Plate processing
  • Dynamic water jet cutting
  • Plate shearing
  • Saw cutting
  • Plasma cutting and high quality plasma cutting
  • Machine cut rings and discs

Penn Stainless Alloy 330 Plate and Processed Flat Bar provides superior resistance to corrosion and heat exposure, in even the most demanding environments.

Corrosion Resistance:

  • Provides high level of corrosion resistance especially with regards to oxidation, carburization, and nitridation
  • Has great oxidation resistance and resists scale formation up to about 2000°F due to its chromium and nickel content
  • Excellent resistance to carburization due to its 34 to 37% nickel and silicon content
  • Exhibits resistance to nitrogen containing atmospheres where the oxygen content is low
  • High nickel content also makes it highly resistant to chloride stress corrosion cracking and sigma phase embrittlement


Alloy 330 will not respond to heat treatment; will only harden upon cold work


Rigid mounts, sulfurized lubricants, positive feeds and slow speeds are recommended for machining grade 330 stainless steel.


Grade 330 stainless steel can be welded using GAW techniques.

Hot Working

Hot working of grade 330 stainless steel can be performed at 1149 to 1177°C (2100 to 2150°F).

Cold Working

It is difficult to perform cold working in grade 330 stainless steel as the steel has high strength and work hardening rate. However, this steel can be cold worked using strong forces.


Grade 330 stainless steel can be annealed at 1121 to 1204°C (2050 to 2200°F).


Chemical Properties:

Element Average Nominal %
Chromium 18.00 – 22.00
Nickel 34.00 37.00
Carbon 0.08 Max
Silicon 1.00 – 1.50
Manganese 2.00 Max
Phosphorus 0.03 Max
Sulfur 0.03 Max
Copper 1.00 Max
Iron Balance

Mechanical Properties:

Tensile Strength – ksi (min.) 0.2% Offset Yield Strength – ksi (min.) Elongation in 2 inches – % (min.) Hardness – Rockwell B
70 30 30 90

Physical Properties:

(lb. / cu. in.)
Specific Gravity Specific Heat
(Btu/lb Deg F – [32-212 Deg F])
Magnetic Permeability Modulus of Elasticity Tension
0.289 7.99 0.11 1.02 28.5

330 Plate and Processing Flat Bar