{"id":805,"date":"2026-08-07T15:06:29","date_gmt":"2026-08-07T09:36:29","guid":{"rendered":"https:\/\/www.stainlessinox.com\/blog\/?p=805"},"modified":"2026-06-25T15:17:32","modified_gmt":"2026-06-25T09:47:32","slug":"difference-between-perforated-chequered-and-shim-duplex-steel-31803-plates","status":"publish","type":"post","link":"https:\/\/www.stainlessinox.com\/blog\/difference-between-perforated-chequered-and-shim-duplex-steel-31803-plates\/","title":{"rendered":"Difference Between Perforated, Chequered, and Shim Duplex Steel 31803 Plates"},"content":{"rendered":"

Duplex Steel UNS S31803 is a dual-phase stainless steel combining austenitic and ferritic microstructures, which gives it higher mechanical strength and better corrosion resistance than most standard grades. It handles aggressive industrial environments well. Not all applications require the same platform. Perforated plates, chequered plates and <\/span>Duplex Steel S31803 shim sheets<\/b><\/a> are three distinct product variants, each suited to specific functional requirements.<\/span><\/p>\n

What Are Duplex Steel 31803 Plates?<\/b><\/h2>\n

Duplex Steel 31803 Plates<\/b> are produced as per ASTM A240 specification under the designation UNS S31803. The material has around 22% chromium, 5% nickel and 3% molybdenum, and provides a minimum tensile strength of 620 MPa and a higher yield strength than standard austenitic grades. The duplex microstructure also provides strong resistance to chloride stress corrosion cracking, which is a major concern in offshore, marine and chemical processing applications.<\/span><\/p>\n

The high strength-to-weight ratio is a practical advantage. Components can be fabricated with less material while still meeting load requirements.<\/span> Duplex Steel Plates in this grade handle seawater, acidic media and high-chloride conditions where conventional 304 or 316 grades would fail faster.<\/span><\/p>\n

Types of Duplex Steel 31803 Plates<\/b><\/h2>\n

Duplex Steel UNS S31803 Perforated Plates<\/b><\/h3>\n

Duplex Steel UNS S31803 Perforated Plates<\/b> are manufactured by punching or laser cutting holes through flat plate stock in round, slotted, square or hexagonal patterns based on the application. Open area reduces component weight and allows controlled passage of fluid, air or particles. In filtration systems, hole geometry manages flow rate and separation. Ventilation setups, food processing decks, chemical plant internals, and noise control enclosures all use these plates, where corrosion resistance and perforation function both matter.<\/span><\/p>\n

Duplex Steel 31803 Chequered Plates<\/b><\/h3>\n

Duplex Steel 31803 Chequered Plates<\/b> are produced with a raised lozenge or teardrop pattern rolled into the plate surface during manufacturing. This raised profile increases surface friction and is the main reason these plates get specified for flooring and access areas. The base material retains full load-bearing capacity. Duplex Steel Chequered Plates are used on industrial walkways, staircases, offshore platform decks and marine vessel surfaces where wet conditions and constant foot traffic demand reliable anti-slip performance.<\/span><\/p>\n

Duplex Steel S31803 Shim Sheets<\/b><\/h3>\n

Duplex Steel S31803 Shim Sheets<\/b> are precision cold-rolled flat sheets supplied in thicknesses typically ranging from 0.05 mm to 3 mm. These are not structural components. They correct gaps, adjust spacing, and align mating parts in mechanical assemblies. Duplex Steel 2205 Shim Sheets are used under motor mounts, bearing housings, pump casings, and valve bodies. The duplex grade prevents in-place corrosion that would otherwise distort the dimensional correction the shim was installed to achieve.<\/span><\/p>\n

Key Differences Between Perforated, Chequered, and Shim Duplex Steel 31803 Plates<\/b><\/h2>\n

All three products share the same base material but serve different engineering functions. Selecting the wrong form creates performance problems that the material grade alone cannot resolve.<\/span><\/p>\n

Surface Design Comparison<\/b><\/h3>\n

Perforated plates have holes cut through the full thickness for open-area flow and filtration. Chequered plates have raised projections formed into the top surface, increasing friction without removing any material. Shim sheets are completely flat and smooth: any surface texture would compromise their precision dimensional function.<\/span><\/p>\n

Functional Application Difference<\/b><\/h3>\n

Perforated plates address filtration, drainage, and ventilation. Chequered plates handle anti-slip flooring and structural access areas. Shim sheets manage precision alignment and gap correction in mechanical assemblies. These are three different engineering problems, even when all three products are manufactured from <\/span>Duplex Steel UNS S31803<\/b> to ASTM A240.<\/span><\/p>\n

Thickness and Structural Characteristics<\/b><\/h3>\n

Chequered plates are typically supplied in 3 mm to 10 mm or heavier, suited to structural use. Perforated plates cover a broader range depending on the application. Shim sheets are the thinnest, often below 1 mm, and carry no structural load. Mechanical performance reflects this distinction across all three forms.<\/span><\/p>\n

Fabrication and Processing<\/b><\/h3>\n

Perforated plates require secondary processing, hole punching or laser cutting, after the base plate is formed. Chequered plates are formed by rolling with a patterned roll during production. Shim sheets are cold-rolled to precise thicknesses and sheared or laser-cut to size. Welding suitability is similar across all three since the base material is the same, though shim sheets are rarely welded in their intended application.<\/span><\/p>\n

Advantages of Duplex Steel 31803 Across All Plate Types<\/b><\/h2>\n

All three product forms benefit from the same base material properties. Industrial Stainless Steel Plates in this grade consistently outperform standard austenitic grades in demanding environments.
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