Duplex 2205 Flat Washers
ISO 7089 / ISO 7090ASTM A240
Duplex 2205 flat washers provide strong, corrosion-resistant bearing faces for compatible chloride-process equipment and washdown assemblies. Their dimensions can be selected for a compact flange spotface or a wider slotted support, with thickness matched to the unsupported span.
- MOQ
- 100PCS
- Samples · typical
- ~20 days
- Production · typical
- 25–35 days
- Heat treatment
- Solution annealed and quenched
EN 10204 3.1 MTC + heat-number traceability
Which standard is on your order?
Raw Material Specifications
Dimension Reference
Heat Treatment
Solution annealed and rapidly cooledSolution annealing followed by rapid cooling controls harmful precipitates and preserves the ferrite–austenite structure.
What we can make in Duplex 2205
Normal series
Use under bolt heads and nuts on machined equipment faces with adequate surrounding seat area. The bore must clear the bolt shank and under-head radius so the washer lies flat.
Larger outside diameter
Use over slots, oversized holes and softer mounting surfaces to spread the bearing load. Washer thickness matters as well as diameter: a thin wide washer can dish over an unsupported opening.
Square & special profiles
Use on channel supports, slotted bases and special mounting pads where a round washer leaves insufficient support. Profile and hole position keep the bearing plate seated across the actual opening.
- Geometry
- Bore × outside diameter × thickness
- Forms
- Round · Square · Drawing profiles
- Function
- Bearing surface · Spacing
- Sizing
- Metric · Inch
- Final condition
- Solution annealed and quenched
- Inspection
- Bore · Outside diameter · Thickness · Burrs
Manufacturing route
Small lots can be machined from suitable stock; repeat production uses cut or punched blanks with bore and outer edge finishing.
Heat treatment & final condition
Solution treatment and cooling control the duplex structure. Subsequent processing must preserve the ordered corrosion and mechanical condition.
Finished geometry
Thickness, flatness and edge finish establish the bearing geometry; the washer is not labelled hardened solely because the alloy is corrosion resistant.
Where Duplex 2205 fits — and what matters
Split-case & multistage pump casings
Duplex 2205 Flat WashersPump cover nuts need a flat seat that carries their pressure without sinking into a small contact area. 2205 washers provide a strong duplex bearing face in compatible process-water service. The outside diameter must stay on the machined spotface, and the bore must clear the stud without leaving an excessively narrow ring.
Connection requirements
- Spotface and stud diameters
- Washer thickness and bearing load
- Process-water chloride exposure
Corrosive washdown packaging conveyors
Duplex 2205 Flat WashersWashdown conveyor supports commonly use slots for alignment. A 2205 washer spreads nut pressure across the slot while resisting suitable chloride-bearing cleaning water. Its thickness is selected for the gap it bridges; a large, thin washer can bend even when the alloy itself has ample tensile strength.
Connection requirements
- Slot width and washer span
- Support plate thickness
- Cleaning regime and retained moisture
Black-liquor evaporators & concentrators
Duplex 2205 Flat WashersOn evaporator cover hardware, duplex washers form replaceable seats beneath the nuts. 2205 is useful where the liquor and cleaning chemistry are compatible with the alloy. Smooth, flat faces distribute the nut load, while the exposed outer edge and underside are the locations most likely to collect process residue.
Connection requirements
- Liquor and cleaning exposure
- Nut footprint
- Face finish, thickness and flatness
Same washer. Different material priorities.
Duplex 2205 material dataSuper Duplex 2507 Flat Washers
2507 washers combine high strength with super duplex chloride resistance for seawater covers, brackets and brine equipment. They are useful where the bearing face is highly loaded and 2205 offers insufficient corrosion margin. The underside is still a crevice, making temperature, deposits and chlorination relevant to the washer selection.
254 SMO Flat Washers
254 SMO flat washers provide replaceable bearing faces beneath bleach-plant and seawater-equipment fasteners. The six-moly austenitic grade offers greater resistance to localized chloride attack than common 316. Supported diameter, thickness and hardness are selected for the pressure applied by the nut or bolt head.
Inconel 625 Flat Washers
Inconel 625 washers provide replaceable bearing faces on seawater-pump covers and chemical flange joints. Their nickel-chromium-molybdenum corrosion resistance is useful where liquid remains beneath the nut after exposed surfaces dry. Thickness and outside diameter let the washer support the nut pressure on a compact spotface or span a wider support opening.
From drawing to documented delivery
- 01Drawing & BOMForm, dimensions and quantity
- 02Material & formingGrade, heat and manufacturing route
- 03Final inspectionGeometry, threads and ordered tests
- 04Documents & dispatchLot records and identified packing
Order documents
- Material identity
- S31803 / S32205 · heat number · ordered condition
- Final-part acceptance
- Final condition and any ordered phase-balance, corrosion or impact testing.
- Dimensional record
- Bore · Outside diameter · Thickness · Burrs
- Traceability
- EN 10204 3.1 material certificate · production lot · identified packing
Build your Duplex 2205 washer enquiry
Questions about Duplex 2205 flat washers
Should the washer use the same alloy as the bolt?
The wetted assembly may need matching corrosion resistance, but the washer also needs sufficient bearing strength and thickness. The bolt grade does not by itself specify a hardened or load-rated washer.