Special Stainless Steel Alloys
Wakefield Metals can offer a range of stainless steel special alloys on indent such as 2205, 2304, LDX2101, 430,445, 404GP, 3CR12, 904L, 254SMO and 17-4 PH.

Special Alloys

Complementing our standard stainless steel range, Wakefield Metals can offer  the following alloys on indent basis.


LDX2101® is a duplex (ferritic/austenitic) stainless steel grade with a useful combination of corrosion resistance and high strength. Because it has almost no molybdenum and a low nickel content the grade is an economical alternative to 304 or 316 in some applications. In 2101 nickel is largely replaced by manganese and molybdenum’s corrosion resistance role largely taken over by nitrogen. Yield strength is about double that of the standard austenitic grades 304 and 316. LDX2101 was developed by Outokumpu as a “lean duplex” grade; it has since been allocated designations UNS S32101 and 1.4162 in the American and European standards systems. It also has ASME pressure vessel endorsement, initially under Code Case 2418.


2205 is the most widely used duplex (ferritic/austenitic) stainless steel grade. It finds applications due to both excellent corrosion resistance and high strength.
The standard S31803 composition has over the years been refined by many steel suppliers and the resulting restricted composition range was endorsed as UNS S32205 in 1996. S32205 gives better guaranteed corrosion resistance, but much of the S31803 currently produced also complies with S32205.


2304 is a duplex (ferritic/austenitic) stainless steel grade with a useful combination of corrosion resistance and high strength. Because it has almost no molybdenum the grade is an economical alternative to 316 in some applications. 2304 is not generally suitable for use at temperatures above 300°C as it suffers from precipitation of brittle micro-constituents, nor below -50°C because of its ductile-to-brittletransition.


2507 is one of a group of “super duplex” grades, combining high strength with exceptional corrosion resistance. 2507 is very highly resistant to general corrosion and to pitting and crevice corrosion in high chloride, hot environments. Its duplex structure also results in excellent resistance to stress corrosion cracking. Like other duplex (ferritic/austenitic) grades the super duplex grades are not suitable for high or low temperature service. 2507 is not recommended for temperatures below -50°C or above +300°C, because of reduced toughness outside this range. The high strength favours applications in pressure vessels and for marine and other shafts


253MA is a grade combining excellent service properties at high temperatures with ease of fabrication. It resists oxidation at temperatures up to 1150°C and can provide superior service to Grade 310 in carbon, nitrogen and sulphur containing atmospheres. 253MA® is a trademark owned by Outokumpu Stainless AB. The standard grade designation covering this grade is UNS S30815. Other mills produce grades compliant with UNS S30815, including Sirius S15®. 253MA contains a fairly low nickel content, which gives it some advantage in reducing sulphide atmospheres when compared to high nickel alloys and Grade 310. The inclusion of high chromium, silicon, nitrogen and cerium contents gives the steel good oxide stability, high elevated temperature (creep) strength and excellent resistance to sigma phase precipitation. The austenitic structure gives this grade excellent toughness, even down to cryogenic temperatures.


Grade 904L is a non-stabilised 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 904L is used less commonly than in the past.


This “utility stainless steel” is a fairly recent modification of 12% chromium stainless steel grades 409 and 410. It has been developed as a readily fabricated, low cost grade, exhibiting good resistance to wet abrasion and mildly corrosive environments. This grade is covered by Euronorm designation 1.4003 and also ASTM UNS S40977 / S41003.


Grade 430 is a ferritic, straight chromium, non-hardenable grade, combining good corrosion resistance and formability characteristics with useful mechanical properties. Its ability to resist nitric acid attack permits its use in specific chemical applications but automotive trim, indoor panelling such as refrigeration cabinets and appliance components are its largest fields of application. This grade is only readily available in sheet and coil (up to 1.2mm thick), most commonly in BA or 2B finishes, or polished to No4. The BA finish sheet has a quite bright, reflective appearance. Grade 430F is the free-machining version of this grade, produced in bar form for high speed machining in automatic screw machines.

630 or 17-4PH

Grade 630 martensitic precipitation hardening stainless steel has a combination of high hardness and strength after suitable heat treatment. It also has similar corrosion and heat resistance to Grade 304. The terms “Type 630” and “17-4PH” refer to the same grade. The great benefit of this grade (and of other precipitation hardening grades of stainless steel) is that they are generally supplied in the solution treated condition, in which they are just machinable, and then can be age hardened to achieve quite high strengths. This aging treatment is so low in temperature that there is no significant distortion. These grades are therefore well suited to production of long shafts, which require no re-straightening after heat treatment.

For a comprehensive list of information on these special alloys please refer to our sister companies website

Contact us on info@wmetals.co.nz for more information or indent pricing on these special alloys.

Special Alloys

Heat Resistance
  • LDX 2101, 2205, 904L, 17-4PH

Grade 404GP

Ferritic Alloy
  • Chemistry
  • Mechanical Properties
  • Corrosion Performance
  • Physical Properties

Grade 445M2

Ferritic Alloy
  • Features
  • Formability
  • Weldability
  • Composition


New Ferritic Weldings
  • Filler Metals
  • Shielding Gas
  • Heat Treatment
  • Clean up


  • Product Compliance
  • Typical Applications
  • Corrosion Resistance
  • Expected Performance