Incoloy 800HT Flat washers
ISO 7089 / ISO 7090ASTM B409
For Incoloy 800HT washers, tightly controlled carbon and Al + Ti for creep duty 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
- Solution annealed (≥1149°C / 2100°F)
EN 10204 3.1 MTC + heat-number traceability
Which standard is on your order?
Raw Material Specifications
Dimension Reference
Heat Treatment
Solution annealedThe specified solution treatment develops the controlled grain structure needed for sustained high-temperature creep duty.
What we can make in Alloy 800HT
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 (≥1149°C / 2100°F)
- 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 annealing at a minimum of 1149°C (2100°F) establishes the coarse-grain condition used for creep resistance. The heat-treatment record and grain-size result identify this delivery state.
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 800HT fits — and what matters
Furnaces & Heat Treatment
Heat-treatment fixturesIncoloy 800HT flat washers spread bolt or nut bearing load across heat-treatment fixtures, protecting the seating surface and bridging the specified hole clearance. Hot dwell, thermal expansion and repeated furnace cycles set the working load.
Power & Turbines
Boiler-duct supports and hot auxiliary bracketsIncoloy 800HT flat washers spread bolt or nut bearing load across boiler-duct supports and hot auxiliary brackets, protecting the seating surface and bridging the specified hole clearance. Hot dwell and start-stop expansion act on the supported or moving component.
Chemical Processing
Reformer tube-support and heater fixturesIncoloy 800HT flat washers spread bolt or nut bearing load across reformer tube-support and heater fixtures, protecting the seating surface and bridging the specified hole clearance. These parts work in the heated equipment zone, where sustained loading and thermal expansion govern their section and clearance.
Same washer. Different material priorities.
Incoloy 800HT material dataIncoloy 800
UNS N08800- Carbon
- ≤0.10%
- What changes
- General heat and oxidation resistance; no grain-size requirement in the family comparison.
Incoloy 800H
UNS N08810- Carbon
- 0.05–0.10%
- What changes
- Controlled carbon and coarse-grain condition for creep and stress-rupture duty.
Incoloy 800HT
UNS N08811 · Current grade- Carbon
- 0.06–0.10%
- What changes
- Tighter carbon and Al + Ti control (0.85–1.20%), with solution treatment and coarse grain for creep duty.
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 N08811 · heat number · ordered condition
- Final-part acceptance
- UNS grade, carbon and alloy chemistry, solution-treatment record and ordered grain-size evidence.
- Dimensional record
- Bore · Outside diameter · Thickness · Burrs
- Traceability
- EN 10204 3.1 material certificate · production lot · identified packing
Build your 800HT washer enquiry
Questions about 800HT 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.