Monel 400 Flat Washers
ISO 7089 / ISO 7090ASTM B127
Monel 400 washers provide nickel-copper bearing surfaces for marine bolted joints and cooling-water equipment. Their outside diameter spreads the fastener load onto the supporting part, while thickness and material condition determine resistance to permanent seating deformation.
- MOQ
- 100PCS
- Samples · typical
- ~20 days
- Production · typical
- 25–35 days
- Heat treatment
- Annealed
EN 10204 3.1 MTC + heat-number traceability
Which standard is on your order?
Raw Material Specifications
Dimension Reference
Heat Treatment
Annealed; cold worked for higher strengthAnnealing restores ductility after working, while the specified amount of cold work sets higher-strength conditions without aging.
What we can make in Monel 400
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 · Cold worked
- 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 400 fits — and what matters
Shipboard cooling lines
Monel 400 Flat WashersCooling-line flange nuts bear onto a relatively small annular area. Monel 400 washers provide a replaceable seat in suitable marine-water service and help avoid direct rubbing of the nut on the flange. Their thickness must carry the nut pressure without leaving a dished washer after tightening.
Connection requirements
- Nut footprint and seating pressure
- Washer thickness and condition
- Flange drainage
Deck winches & topside equipment
Monel 400 Flat WashersDeck brackets can have clearance holes wider than the bolt shank. A Monel 400 washer spreads the head or nut load over the support while resisting marine exposure. The outside diameter needs to cover the opening fully, with enough thickness to bridge any unsupported edge.
Connection requirements
- Opening size and edge distance
- Washer span and support thickness
- Saltwater wetting and drying
Seawater pumps
Monel 400 Flat WashersPump-cover washers give each nut a consistent bearing face during maintenance. Monel 400 is useful where the washer sees suitable seawater exposure and its condition meets the seating load. The inside edge must clear the stud transition so the washer rests flat against the casing rather than rocking on a fillet.
Connection requirements
- Stud transition clearance
- Spotface flatness
- Washer hardness and installed load
Same washer. Different material priorities.
Monel 400 material dataMonel 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.
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.
Duplex 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.
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 N04400 · 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 400 washer enquiry
Questions about 400 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.