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NSSC’s Duplex Stainless Steel Perforated Metal

Duplex stainless steel can solve these problems!

For problems in the production of food/beverage products and pharmaceuticals

Want to reduce the replacement frequency of equipment used in food factories.

Want to lower the man-hours required to polish chemicals and pharmaceuticals.

Want to stabilize costs without price fluctuations.

Want to use environmentally friendly equipment.

Changing from conventional stainless steel to a duplex stainless steel Perforated Metal can solve any problems!

By replacing the strainer with a "duplex stainless steel" Perforated Metal made of a material that is stronger and more durable than conventional products, the frequency of equipment replacement can be reduced and the use of reinforcement materials can be reduced, resulting in cost savings.

What is duplex stainless steel ?

Duplex steel is different from double-layer steel. Duplex stainless steel has advantages of both austenitic and ferritic structure.
Duplex stainless steel is made by increasing the Cr content and decreasing the Ni content.

Features of Duplex stainless steel sanitary strainer

High Strength

Solves strength problem of SUS304・SUS316L wire mesh strainer‬‬‬‬
Duplex stainless steels have twice the strength and higher hardness properties than conventional stainless steels

  • Twice the strength (0.2% yield strength) enable to lead to lighter weight and thinner wall, also it has excellent springness.
  • High hardness and good abrasion resistance, it is hard to dent even if objects hit it.

High corrosion resistance

Excellent resistance to pitting corrosion and stress corrosion cracking‬‬‬‬
Duplex stainless steels have excellent resistance to pitting corrosion and stress corrosion cracking in a chloride environment

  • Longer equipment life
  • Reduction of life cycle costs of strainer.


Excellent buffing and polishing properties‬‬‬‬
Compared to conventional stainless steel, buffing is easier and surface luster is more easily achieved.

  • Reduction of the man-hours for polishing

Lower thermal expansion

Less thermal expansion and contraction than SUS304‬‬‬‬
Low coefficient of linear expansion prevents expansion, contraction, and thermal deformation due to heating and cooling.

  • Mitigation of thermal deformation and thermal fatigue

Resource savings

Uses much smaller amounts of Ni and Mo.‬‬‬‬
Due to its low content of rare materials, this material is not easily affected by price fluctuations and more environmentally friendly than conventional stainless steels.

  • Less susceptible to raw material price fluctuations
  • Environmentally friendly materials

Cost reduction

Reduce cost by reducing weight

Product specifications

Applicable specification of Laser drilled Duplex Stainless Steel and Perforated Duplex Stainless Steel

①SUS821L1(NSSC 2120®)
Hole size
Open area
Laser φ0.035 0.5t 3.5% #400 900×1800
φ0.045 5.0% #300
φ0.075 6.5% #200
φ0.110 10.0% #150
φ0.155 14.0% #100
φ0.200 17.0% #80
φ0.270 19.0% #60
φ0.320 22.0% #50
φ0.410 22.0% #40
φ0.560 25.0% #30
Perforating φ0.700 P1.5 19.7% #24 500×500
φ0.800 P1.6 22.7% #24
φ0.900 P1.8 22.7% #20
φ1.000 P2 22.7% #18

②SUS329J1 equivalent(NSSC®2351)
Hole size
Open area
Laser φ0.410 0.8t 22.0% #40 900×1800
φ0.560 25.0% #30
Perforating φ0.800 22.7% #24 500×500
φ0.900 P1.6 32.6% #20
φ1.000 P1.5 40.3% #18

※The pattern of Laser screen is Random Straight
※The pattern of Perforated metal is 60 degree staggered.

Main chemical composition・Pitting Resistance Equivalent Number(PREN)

classification Cr Ni Mo Mn N Rare
21 2 - 3 0.17 23 25
23 5 1 1 0.17 29 30
SUS304 18 8 - 1 0.04 26 19
SUS316L 18 12 2.5 1 0.02 32.5 26

●Compared to conventional stainless steel,Duplex Stainless Steel has a higher Cr,lower Ni,Lower Mo,higher N.
It is an eco-friendly material with low content of rare metals. ●NSSC 2110® and NSSC 2351® have a higher PREN than SUS 304 and SUS 316L,respectively.

*1 Sum total of rare metal=Cr%+Ni%+Mo%
*2 PREN=Cr%+3.3×Mo%+16×N%

Mechanical Properties

classification 0.2%Yield
570 792 31 256
613 830 29 264
SUS304 300 654 56 170
SUS316L 281 561 53 143

●Compared to conventional stainless steel,

Physical properties

Classification Density
Modulus of
Specific heat
Coefficient of
7.80 200 0.5 16.0 13.7 Yes
7.80 200 0.5 15.2 13.1 Yes
SUS304 7.93 193 0.5 16.3 17.3 No
SUS316L 7.98 193 0.5 16.3 16.0 No

●Compared to conventional stainless steel,

Precautions for welding duplex stainless steel

NSSC's Duplex stainless steel NSSC2120®(SUS821L1) and NSSC®(Equivalent to SUS329J1) have greatly been improved weldability and can be welded under the same conditions as SUS304.
Please note the following.

  • 1Use of specialized welding materials
    (diagram below) recommended
    Welding without welding material is also possible, but the characteristics of the weld must be checked beforehand.
  • 1Proper heat input control (Avoid Low heat input / High heat input and Spot welding. Interpass temperature below 100 degree C is required.)
  • 1Avoid using hydrogen as a shielding gas
  • 1Weld scale removal

Recommended welding materials

Steel type Covered arc-welding electrode TIG welding rod Flux cored wire electrode
NSSC2120® Similar metal (The lean duplex stainless steel)
Type 2209
Type2209 Similar metal (The lean duplex stainless steel)
Type 2209
NSSC®2351 Type2209 Type2209 Type2209

Dissimilar material welding of duplex stainless steel

SUS304 type Type2209,309LMo,309L
SUS316 type Type2209,309LMo

Reference example

Food factory large tank

Thickness 3~8mm
Conventional stainless steel SUS304

Thickness 2~6mm
Duplex stainless steel SUS821L1

By converting a large tank in a food factory to duplex stainless steel, we were able to reduce the plate thickness from 3 to 8 mm to 2 to 6 mm.
Steel weight has been reduced by 25% to achieve weight savings.

The crane used was downsized to reduce equipment costs.
Mobile sanitary tanks have also been downsized for improved transportability.

Food factory retort sterilization trays

Conventional stainless steel SUS304、aluminum resin

Duplex stainless steel SUS821L1

Replacing sterilization trays in food plants with duplex stainless steel can increase strength, reduce reinforcement, make trays lighter, and reduce processing costs.

Low thermal expansion makes it resistant to heat-induced deformation and distortion, extending the maintenance cycle and extending service life.

Press Release

Okutani developed a duplex stainless steel strainer for food and medical applications.
(Joint developed with NS Stainless Corporation)
Okutani has developed a perforated strainer made of Duplex stainless steel for production equipment for food and medical products in joint-development with NS Stainless Corporation