
Incoloy 020 Flat washers
ISO 7089 / ISO 7090ASTM B463
For Incoloy 020 washers, nickel-rich austenitic performance in sulfuric-acid equipment is only useful with a bearing section that stays flat under load. Bore, outside diameter and thickness match the head or nut to the supported member.
- 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
AnnealedThe specified anneal restores ductility and the corrosion-resistant supplied condition after hot or cold working.
What we can make in Alloy 020
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
- 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 020 fits — and what matters

Chemical Processing
Mixer drives and process-equipment bracketsIncoloy 020 flat washers spread bolt or nut bearing load across mixer drives and process-equipment brackets, protecting the seating surface and bridging the specified hole clearance. Process liquid can remain at the contact after the exposed surface drains.

Pumps, Valves & OEM
Actuator mounts and pump baseplatesIncoloy 020 flat washers spread bolt or nut bearing load across actuator mounts and pump baseplates, protecting the seating surface and bridging the specified hole clearance. Repeated maintenance makes fit, engagement and access part of the component specification.

Mining & Mineral Processing
Leach-equipment and dosing-skid supportsIncoloy 020 flat washers spread bolt or nut bearing load across leach-equipment and dosing-skid supports, protecting the seating surface and bridging the specified hole clearance. Leach solution and deposits act on the installed part; corrosion duty is separate from abrasive wear.
Same washer. Different material priorities.
Incoloy 020 material dataHastelloy C-276
Resistance to chemically aggressive, mixed process streams.
- Connection priority
- Bearing pressure and resistance to dishing
- Process liquid and shutdown chemistry
- C-276 is selected for its nickel–chromium–molybdenum–tungsten chemistry. Residual product, cleaning liquid and oxidising contamination can expose a sheltered connection differently from the main flow. Include liquid retained at the two bearing faces and the bore around the shank in the exposure description.
Inconel 625
Solid-solution strength and resistance to aggressive process liquids.
- Connection priority
- Bearing pressure and resistance to dishing
- Annealed or solution-annealed 625
- The delivery condition affects strength and high-temperature response. Keep the specified condition with the component’s mechanical acceptance; 718-style aging is not the strengthening route for 625. Include liquid retained at the two bearing faces and the bore around the shank in the exposure description.
Hastelloy C-22
Corrosion resistance across oxidising and reducing process exposures.
- Connection priority
- Bearing pressure and resistance to dishing
- Production and cleaning cycles
- C-22’s chromium-bearing chemistry is relevant when chemical exposure changes between operating and cleaning cycles. Include both liquids when comparing it with C-276 or a B-type nickel alloy. Include liquid retained at the two bearing faces and the bore around the shank in the exposure description.
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 N08020 · 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 020 washer enquiry
Questions about 020 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.