UNS N08800

Incoloy 800 Flat washers

ISO 7089 / ISO 7090ASTM B409

For Incoloy 800 washers, heat and oxidation resistance for thermal 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

Upload drawing

Which standard is on your order?

Raw Material Specifications

Dimension Reference

Heat Treatment

Annealed

Annealing reduces work hardening and restores ductility for the specified supplied condition.

What we can make in Alloy 800

normal flat washer, top view

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.

large flat washer, top view

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 flat washer, top view

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 ordered annealed or solution-treated state is retained in the lot record; forming and machining do not replace the specified thermal 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 800 fits — and what matters

Heat-treatment workshop with horizontal furnaces, green pipes and a blue motor

Furnaces & Heat Treatment

Heat-treatment fixtures

Incoloy 800 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.

Bore clearance · bearing diameter · thickness
Furnaces & Heat Treatment fasteners
Technician inspecting blade rows beneath a large turbine rotor

Power & Turbines

Boiler-duct supports and hot auxiliary brackets

Incoloy 800 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.

Bore clearance · bearing diameter · thickness
Power & Turbines fasteners
Silver distillation columns with access ladders and yellow service platforms

Chemical Processing

Reformer tube-support and heater fixtures

Incoloy 800 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.

Bore clearance · bearing diameter · thickness
Chemical Processing fasteners

Same washer. Different material priorities.

Incoloy 800 material data

Incoloy 800

UNS N08800 · Current grade
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 800H flat washers

Incoloy 800HT

UNS N08811
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.
Incoloy 800HT flat washers

From drawing to documented delivery

Heat treatment
Heat treatment
CNC machining
CNC machining
Rockwell hardness testing
Rockwell hardness testing
Wooden-crate packing
Wooden-crate packing
  1. 01Drawing & BOMForm, dimensions and quantity
  2. 02Material & formingGrade, heat and manufacturing route
  3. 03Final inspectionGeometry, threads and ordered tests
  4. 04Documents & dispatchLot records and identified packing

Order documents

Material identity
UNS N08800 · 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 800 washer enquiry

QUOTE LIST ITEMIncoloy 800 flat washers; UNS N08800; Plain washer

Questions about 800 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.

Technical references & photo credits