Inconel 625 Flat Washers
ISO 7089 / ISO 7090ASTM B443
Inconel 625 flat washers provide a corrosion-resistant bearing surface beneath nuts and bolt heads on seawater equipment and chemical plant. Bore, outside diameter and thickness can be matched to the fastener and the available seat, including wider washers for slotted supports.
- MOQ
- 100PCS
- Samples · typical
- ~20 days
- Production · typical
- 25–35 days
- Heat treatment
- Annealed / solution annealed
EN 10204 3.1 MTC + heat-number traceability
Which standard is on your order?
Raw Material Specifications
Dimension Reference
Heat Treatment
Annealed or solution annealedAnnealing restores ductility, while the higher-temperature solution anneal prepares 625 for creep-resistant service without precipitation aging.
What we can make in Alloy 625
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
- Annealed · solution annealed
- 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
The final annealed or specified strengthened condition is linked to the lot; an aging treatment is not assumed for a solid-solution alloy.
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 625 fits — and what matters
Seawater pumps
Inconel 625 Flat WashersUnder the nuts on a seawater-pump cover, a 625 washer gives the rotating nut a replaceable bearing face. Its corrosion resistance is useful around wet bolt holes and leakage paths. The washer bore must clear the stud while its outside diameter stays fully supported on the casing flange.
Connection requirements
- Stud clearance and washer bore
- Available flat seating diameter
- Washer thickness and bearing load
Reactor vessel & manway flanges
Inconel 625 Flat WashersReactor manways are opened for cleaning and internal inspection. Inconel 625 washers separate the nut from the flange seat during repeated tightening, while resisting attack from many chloride-bearing process residues. A wider washer can spread contact over a larger seat; sufficient thickness keeps it from dishing under the nut.
Connection requirements
- Manway stud and nut dimensions
- Residue chemistry at the outer flange
- Outside diameter, thickness and flatness
Deck winches & topside equipment
Inconel 625 Flat WashersOn topside equipment brackets, washers bridge clearance holes and spread bolt-head pressure onto the support. Inconel 625 is useful where salt spray and chemical washdown reach the underside of the washer. Slot width and edge distance set the bearing footprint, rather than the bolt diameter alone.
Connection requirements
- Hole or slot width
- Support material and coating
- Washdown exposure and washer footprint
Same washer. Different material priorities.
Inconel 625 material dataInconel 718 Flat Washers
Age-hardened Inconel 718 washers are useful beneath high-preload turbine and valve fasteners, particularly where the seat diameter is restricted. Their strength helps resist permanent indentation at the bearing face. This is a different priority from choosing 625 washers mainly for wet corrosion resistance; the 718 heat-treatment condition belongs on the washer order.
Hastelloy C-276 Flat Washers
C-276 washers are a strong candidate for acid-plant flanges and scrubber hardware exposed to mixed chemical residues. Their purpose is to preserve the bearing surface in aggressive wet service, rather than provide age-hardened strength. Outside diameter and thickness should give the nut a supported seat without creating a thin, easily bent rim.
Monel K-500 Flat Washers
K-500 washers add bearing strength to marine bolted joints while retaining the nickel-copper alloy family used in seawater equipment. They are most useful where the loaded seat is compact. Age-hardened condition and mating fastener load matter more here than a generic seawater label; cathodically protected subsea assemblies require a separate hydrogen-susceptibility review.
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 N06625 · heat number · ordered condition
- Final-part acceptance
- Grade chemistry, supplied condition and ordered mechanical requirements.
- Dimensional record
- Bore · Outside diameter · Thickness · Burrs
- Traceability
- EN 10204 3.1 material certificate · production lot · identified packing
Build your 625 washer enquiry
Questions about 625 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.