303 – 303 stainless is the most machinable of the austenitic grades of ss. With the addition of sulfur
to this grade, the sulfur enhances the alloys machinability which is ordinarily difficult to machine.
Applications for 303 is shafts, valve bodies, valve trim and food industry applications where 304 is
normally used. 303 stainless is resistant to atmospheric corrosion, food products, sterilization
solutions and many organic chemicals as well as a variety of inorganic chemicals.

304 – 304 and 304L (low carbon version) is a low carbon austenitic alloy. By keeping the carbon at
.03% max, it minimizes carbide precipitation during welding.
Applications are the same as 303

310 – Grade 310, combining excellent high temperature properties with good ductility and weldability,
is designed for high temperature service. It resists oxidation in continuous service at temperatures up
to 1150°C provided reducing sulphur gases are not present. It is also used for intermittent service at
temperatures up to 1040°C. Applications for molten salt, sulfur bearing gas and heat exchanger and
recuperator tubing.

316 – 316 is the 2nd most common stainless after 304 and is commonly used in food and surgical
applications. The addition of moly prevents specific forms for corrosion. By keeping the carbon at
.03% max, it has been shown to minimize carbide precipitation during welding. Decreasing the sulfur
will enhance its ability for electro-polishing. It is also known as a marine grade due to the increased
resistance to chloride corrosion in comparison to 304. It is generally used in marine applications and
watches, pharmaceutical equipment, valve bodies, bleaching and dying equipment or the textile and
food industry

.
317 – 317 is a molybdenum-bearing austenitic chrome nickel similar to 316 except the alloy content is
higher. It was developed primarily to more effectively resist the attack of sulfurous acid compounds.

321 – this is titanium bearing stainless and it is stabilized against carbide precipitation. In higher
temperatures the carbon combines with the titanium to form a harmless titanium carbide leaving the
chrome to maintain full corrosion resistance. 321 is basically 304 modified by adding titanium in an
amount at least 5 times the carbon plus nitrogen contents.

347 – 347 is a columbium/tantalum stabilized austenitic ss. Similar to 321, it has good intergranular-
corrosion compared to typical 18-8 type alloys. It is widely used in aircraft exhausts, expansion joints
and in high temperature chemical processing. It is resistant to atmospheric conditions and should be
considered for applications requiring intermittent heating between 800F and 1650f.

410 – 410 is a hardenable martensitic alloy that is designed for high stress parts that require high
ductility as well as good corrosion resistance. Working temps up to 1200F are acceptable. 410 is
widely used in blades and buckets, steam turbines, turbine wheels, valves, aircraft parts and pumps
and pump shafts.

416 – Grade 416 has the highest machinability of any stainless steel, at about 85% of that of a free-
machining carbon steel. As for most other free-machining stainless steels the improvement in
machinability is achieved by addition of sulphur which forms manganese sulphide inclusions; this
sulphur addition also lowers the corrosion resistance, weldability and formability to below that of its
non-free machining equivalent Grade 410. Grade 416 is sometimes used in the unhardened or
hardened and highly tempered condition because of its low cost and ready machinability.

630 – 17-4 Precipitation Hardening also known as Type 630 is a chromium-copper precipitation
hardening stainless steel used for applications requiring high strength and a moderate level of
corrosion resistance. High strength is maintained to approximately 600 degrees Fahrenheit (316
degrees Celsius).

17-4 PH – A precipitation hardening martensitic stainless steel with Cu and Nb/Cb additions. The
grade combines high strength, hardness (up to 572°F / 300°C), and corrosion resistance. The grade
should not be used at temperatures above 572°F (300°C) or at very low temperatures. It has
adequate resistance to atmospheric corrosion or in diluted acids or salts where its corrosion
resistance is equivalent to Alloy 304 or 430.

15-5 PH – A martensitic precipitation hardened steel – it offers high strength combined with excellent
corrosion resistance. It is similar to 17-4ph in properties, it is more chemically balanced to reduce
ferrite which enhances its transverse properties. It is used when high transverse strength is required
– valve parts, paper mills, aircraft, power generation chemical processing , nuclear and space craft.

904L – 904L is a non-stabilized low carbon high alloy austenitic stainless steel. The addition of
copper to this grade gives it greatly improved resistance to strong reducing acids, particularly
sulphuric acid. It is also highly resistant to chloride attack - both pitting / crevice corrosion and stress
corrosion cracking. This grade is non-magnetic in all conditions and has excellent weldability and
formability. The austenitic structure also gives this grade excellent toughness, even down to
cryogenic temperatures. 904L does have very substantial contents of the high cost ingredients nickel
and molybdenum. Many of the applications in which this grade has previously performed well can
now be fulfilled at lower cost by duplex stainless steel 2205 (S31803 or S32205), so it is used less
commonly than in the past.

2205 Duplex – 2205 duplex has a microstructure that contains both austenitic and ferritic phases and
excellent combination of strength and corrosion resistance. In the annealed condition, it has twice the
strength of a typical austenitic stainless. Used in oil and pas, pumps and pump parts, valves and
chemical and paper manufacturing.

2507 – Commonly known as Super Duplex 2507®, is very similar to UNS S31803 Duplex. The
difference between the two is the contents of chromium and nitrogen are higher in the Super Duplex
Grade which in turn creates higher corrosion resistance as well as a longer lifespan. Super Duplex is
composed of between 24% to 26% chromium, 6% to 8% nickel, 3% molybdenum, and 1.2%
manganese, with the balance being iron. Also found in Super Duplex are trace amounts of carbon,
phosphorus, sulfur, silicon, nitrogen, and copper. Benefits include: good weldability and workability, a
high level of thermal conductivity and low coefficient of thermal expansion, high resistance to
corrosion, fatigue, high resistance to pitting and crevice corrosion, high resistance to stress corrosion
cracking (especially chloride stress corrosion cracking), high energy absorption, high strength, and
erosion. Essentially, the Duplex alloys are a compromise; possessing some of the ferritic stress
corrosion cracking resistance and much of the superior formability of the common austenitic stainless
alloys, more cost effectively than the high nickel alloys.

Alloy 20 – Alloy 20 stainless steel is a super-austenitic stainless alloy developed for maximum
corrosion resistance to sulfuric acid and other aggressive environments not suitable for typical
austenitic grades. Alloy 20 seems to fall in-between both the stainless and nickel categories, as it
does contain characteristics of both; however, the unified numbering system (UNS) does ultimately
recognize it as a nickel based alloy, hence the UNS N08020 number. Alloy 20 is an austenitic nickel-
iron-chromium based alloy with additions of copper and molybdenum. Its nickel content aids in its
chloride ion stress and corrosion resistance. The addition of copper and molybdenum provides
resistance to hostile environments, pitting and crevice corrosion. Chromium adds to its resistance of
oxidizing environments, such as nitric acid, and columbium (or niobium) reduces the effects of
carbide precipitation.

Nickel 200 – Nickel 200 alloy is a commercially pure nickel that exhibits good corrosion resistance. It
is ferromagnetic and has relatively low electrical resistivity. This combination of properties has
allowed its use in a wide variety of applications. Because the alloy displays good corrosion
resistance, it has been used in food handling equipment, caustic solution, and general corrosion-
magnetic and mechanical properties have enabled it to be used in devices requiring magnetic
actuated parts.

Nickel 201 – Nickel 201 alloy is a low carbon modification of Nickel 200 alloy that has found
applications in the electronic industry at temperatures up to 1200°F(649°C). It is preferred to nickel
200 above 600°F(315°C), because of ts better resistance to "creep."

Alloy 400 – (Monel) alloy 400 is a nickel/copper alloy that is easily machined and fabricated. It is
used for its excellent combination of strength, corrosion resistance, ductility and weldability. Very
good in salt water and brackish water and not susceptible to stress corrosion cracking.

Alloy 600 – (Inconel) – alloy 600 is a nickel/chrome/iron alloy good in applications that require
resistance to corrosion and heat. Good for a combination of high strength and good workability under
a wide variety of temperatures. It is acid resistant. Used in jet engines, super heaters, food
processing, steam generators.

Alloy 625 – Alloy 625 (UNS N06625) is a nickel-chromium-molybdenum alloy with excellent strength
from room temperature up to about 1500°F. It maintains good oxidation resistance up to 1800°F and
provides good resistance to corrosion. Some of the applications of this alloy are in chemical
processing, aerospace and marine engineering, pollution-control equipment, and nuclear reactors.

Alloy 800 – (Incoloy) – alloy 800 is a nickel-iron/chrome alloy with additions of copper and moly. Has
excellent resistance to general corrosion, pitting and crevice corrosion in chemicals containing
chlorides and sulfuric, nitric and phosphoric acids. Used for tanks, piping, heat exchangers, pumps,
valves and other process equipment. 800, valves, and other process equipment. Standard product
forms are round, flats, pipe, tube, plate, sheet, strip, and wire.

Alloy 825 – Alloy 825 is a titanium stabilized austenitic nickel/iron/chrome alloy with additions of
copper and moly. It has good resistance to oxidizing and non-oxidizing hot acids. The moly aids in
resistance to pitting and crevice corrosion. Applications include salt water cooled heat exchangers,
offshore piping system tubes, heat exchangers, evaporators and scrubbers.

Alloy C-276 – (Hastalloy) C-276 is a nickel-molly-chrome alloy with the addition of tungsten. It has
excellent corrosion resistance. It is suitable for most chemical process applications. It resists stress
corrosion cracking is resistant to oxidation at temps up to 1900 F. A nickel-iron-chromium alloy with
additions of copper and molybdenum. It also contains niobium for stabilization against sensitization
and resultant intergranular corrosion. The alloy has excellent resistance to general corrosion, pitting,
and crevice corrosion in chemicals containing chlorides and sulfuric, phosphoric, and nitric acids.
Used for tanks, piping, heat exchangers, pumps, valves, and other process equipment. Standard
product forms are round, flats, pipe, tube, plate, sheet, strip, and wire.