Super Duplex 2507 Flat Washers
ISO 7089 / ISO 7090ASTM A240
Super Duplex 2507 washers provide strong bearing surfaces beneath fasteners on seawater and desalination equipment. Their corrosion resistance is useful at wet flange seats and brackets, while outside diameter and thickness are chosen for the area actually carrying the nut or bolt-head load.
- 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 Super Duplex 2507
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 Super Duplex 2507 fits — and what matters
Seawater pumps
Super Duplex 2507 Flat WashersUnder pump-cover nuts, 2507 washers distribute pressure across a replaceable seat exposed to seawater. Their strength helps resist permanent bedding under load. A washer must sit fully on the casing spotface; increasing its diameter beyond that supported area does not create a larger useful bearing surface.
Connection requirements
- Spotface and nut bearing diameters
- Washer hardness and thickness
- Seawater temperature and deposits
Brine booster & high-pressure pumps
Super Duplex 2507 Flat WashersBrine booster pumps expose external cover hardware to concentrated saline leakage. 2507 washers are useful beneath the nuts where super duplex corrosion resistance is required. Flatness and thickness keep the nut load distributed over the seat rather than concentrated at the washer’s inner or outer edge.
Connection requirements
- Brine concentration and temperature
- Cover-seat flatness
- Washer thickness and nut load
Seawater intake screens & gates
Super Duplex 2507 Flat WashersIntake-screen and gate brackets often use slotted holes for alignment. 2507 washers can bridge these slots in seawater exposure while carrying the nut pressure onto the support. The unsupported span sets the required thickness, and the washer outline must leave enough edge distance on the bracket.
Connection requirements
- Slot width and mounting load
- Washer outline and thickness
- Support metal and immersed exposure
Same washer. Different material priorities.
Super Duplex 2507 material dataDuplex 2205 Flat Washers
2205 washers combine useful bearing strength with chloride resistance for pump covers and washdown brackets. They are a practical duplex option where 316-type washers are not adequate for the exposure. For more aggressive seawater crevices, the comparison moves toward 2507, S32760 or a nickel-alloy washer rather than simply increasing washer thickness.
Super Duplex S32760 Flat Washers
S32760 washers suit seawater-pump covers and intake supports requiring this super duplex grade. They provide strong, chloride-resistant bearing surfaces beneath loaded fasteners. On slotted supports, a sufficiently thick section carries the load across the opening while the footprint bears on the available plate.
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
- UNS S32750 · 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 Super Duplex 2507 washer enquiry
Questions about Super Duplex 2507 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.