How Big Does Duplex 2205 Plate Come From North American Stainless?

What thickness and width can I actually order in duplex 2205 plate from North American Stainless? Straight answer: 0.375 to 2.500 inches thick, 48.0 to 60.0 inches nominal width, and 96.0 to 480.0 inches long, delivered in the hot-rolled, annealed-and-pickled No.1 finish.

A purchasing engineer at a skid builder had a drawing in front of her for a half-inch filter housing flange, called the mill, and asked for 2205 plate, whatever they stock. The quote came back inside those numbers and she signed it in ten minutes. Two weeks later the plate arrived, the shop sawed it, and the blank fit. What made that order safe was not the grade name. Her finished thickness, cut width, and cut length all landed inside the supplied window, and that is the part most people skip.

The Thickness, Width, and Length You Can Actually Order

North American Stainless lists duplex 2205 plate across three dimensions, and all three have to clear at once: thickness from 0.375 to 2.500 inches, nominal width from 48.0 to 60.0 inches, and length from 96.0 to 480.0 inches. Thickness is the one everything downstream hangs on, which means you lay your finished part thickness against that band before you spend a minute on width or length. A flange that finishes at 0.750 inch has to be cut from 0.375-inch plate or heavier and machined down, and that 0.375 figure is the floor, not a suggestion.

Most orders go in as a specific thickness plus a cut length inside the 96-to-480-inch band, because the mill stocks plate and cuts to length rather than rolling a custom length per order. A part that finishes at 0.30 inch is a problem: it sits under the 0.375-inch plate floor, and no machining allowance rescues that from plate stock. It has to come from sheet product, which is a different line and a different conversation. Width is the other hard wall. The 48.0-to-60.0-inch range is what the plate comes as, and a part 72 inches across cannot be sawn out of a 60-inch plate no matter how you lay out the nest.

Why Your 2205 Plate Arrives Hot Rolled and Pickled

Duplex 2205 plate leaves North American Stainless hot rolled, annealed, and pickled, which is the No.1 finish. The reason for that sequence is metallurgical, not cosmetic. Hot rolling happens above the recrystallization temperature, which is what lets a slab be reduced to plate thickness, and it also leaves a thick, tightly bonded oxide scale on the surface. Annealing follows because the rolling pass distorts the grain structure and shifts the austenite-to-ferrite balance that duplex depends on. The heat treatment restores that balance and relieves internal stress, which means the plate you machine will not spring or crack from residual rolling strain.

Pickling comes last because hot rolling and annealing both leave a chromium-depleted layer at the surface, and that layer is the first thing to pit in chloride service, which is exactly where 2205 gets specified. Acid pickling strips that depleted skin back to sound metal. A 2B or polished finish is a different production route aimed at a different product, which means a No.1 quote on plate is not a downgrade to argue down. It is the correct starting surface for plate that will be cut, formed, and welded. Ask for polished plate on a half-inch order and you are asking for a finish that does not ship on this product.

NAS 901 Is UNS S32205, Also Called 2205

NAS 901, UNS S32205, and Type 2205 are three labels for one plate chemistry. Because the UNS number is the only globally unique identifier in that set, the trade name 2205 and the mill's internal 901 are aliases, and the document you accept has to read UNS S32205. A mill test report that says duplex in the header and nothing else names a family, not a grade.

That distinction has teeth. An inspector I work with rejects those headers on sight: she reads the grade line for UNS S32205, then traces the heat number to the chemistry and mechanical results printed on the same sheet. The aliasing matters because 2205 gets used loosely across the whole duplex family, including 2507 and the lean duplex grades that are not the same alloy and are not interchangeable for chloride stress-corrosion service. If your paperwork names only the nickname, traceability stops at the word duplex.

From Part Drawing to Plate Order, Step by Step

The sequence that works, in order: read the finished thickness off the drawing; add your machining allowance to it; round up to the nearest stock thickness inside the 0.375-to-2.500-inch band; confirm the cut width fits inside 48.0 to 60.0 inches and the cut length fits inside 96.0 to 480.0 inches; then write No.1 finish on the purchase order. The order matters because everything is anchored to available stock thickness. Pick a nominal size first and let the part be machined out of it, and you can push the job outside the supplied window before anyone notices.

A worked pass: a 0.625-inch finished thickness plus 0.090 inch of machining allowance lands at 0.715 inch, which rounds up to 0.750-inch stock plate, comfortably inside the band. Cut the blank to 44 by 130 inches and you are inside the width and length limits. Now put the window on the PO itself, something like thickness 0.750 in, cut to 44 by 130 in, No.1 finish, UNS S32205, because the mill and your buyer then read the same figure off the same line instead of each assuming the other did the rounding. An order that reads 2205 plate, size per drawing hands the rounding decision to whoever opens the email, and that is how a job gets cut from the wrong thickness.

The One Number That Decides Each Step

Each step in that sequence hinges on one value, and each value fails in its own way. The first is finished thickness, because every allowance later stacks on top of it, so a misread drawing propagates through the whole order. The third is the rounded stock thickness landing inside the supplied thickness band. The fifth is the finish callout, No.1, because the written line on the purchase order outranks any verbal assumption about surface.

Width and cut length are the two dimensions the mill supplies as-is. Width is the harder wall: thickness is a dimension you can remove metal from, buy 0.750 inch, machine to 0.625 inch, and the plate is still a plate, while a blank wider than the plate cannot be recovered by welding two plates together inside a pressure boundary. If the drawing calls for a 62-inch cut and the plate tops out at 60.0 inches, the order is dead before it is placed. Length carries less risk because the mill saws it to order inside the 96-to-480-inch band, so a long cut just consumes more of the plate. Put the machining allowance on the order as a number, not as the phrase plus stock, because plus stock means whatever the shop foreman decides that morning.

How to Confirm the Plate You Ordered Is Correct

Before the saw touches the plate, three checks. Match the heat number stamped or tagged on the plate to the UNS S32205 mill test report that shipped with it. Measure thickness at three points across the plate against the ordered value, all three inside 0.375 to 2.500 inches. Look at the surface: it should be uniformly pickled, gray and even, with no patches of un-pickled black scale. Patches of scale are the visual signature of incomplete pickling, and incomplete pickling means the layer that pickling was meant to remove is still on the surface.

It comes down to traceability. A plate whose size measures perfectly but whose heat number does not match the MTR is not a certified S32205 plate. It is a plate of unknown chemistry that happens to be the right size, and you cannot machine or weld your way back to a grade. Photograph the heat stamp next to the matching MTR line before the plate goes to the saw, so the record exists the day a project engineer asks which heat went into the flange. Match that number first, because everything after it is dimensional, and dimensions are the easy part to fix.