01
Work hardening turns into chatter
A conventional end mill pushes the alloy past its work-hardening threshold. The next pass cuts the hardened skin, not the base metal. Tool life drops to minutes and the wall finish turns into a chatter map.
Nickel-iron-chromium alloy · UNS N08800
Incoloy 800 UNS N08800 CNC Machining
We machine Incoloy 800 parts for furnace fixtures, heat exchanger tubesheets and process hardware. 127 CNC machines, 16 simultaneous 5-axis centers, ±0.005 mm tolerance, 100% inspection before shipment.
±0.005 mmØ400 mm rotary table4,000 mm max sizeRa 0.8–1.6 μmNo MOQNDA on request
15 yearsMachining nickel alloys since 2011
16Simultaneous 5-axis centers
±0.005 mmAchievable tolerance
99.99%Qualification rate
Where nickel-alloy jobs go wrong
Four failures we see on this material
Most of these show up on the first article, not on the drawing.
02
Heat sits in the part
This grade keeps its strength at 800 °C, which means it also keeps heat at the cutting edge. Without high-pressure coolant and a correct feed rate, inserts fail and the surface work-hardens under the next pass.
03
Thin walls move after clamping
Tubesheet lands and combustor liners are often 1.5–3 mm thick. Standard vise pressure distorts them, so the part measures oversize in the fixture and undersize once it is released. The drawing calls out flatness you cannot hold that way.
04
Repair welding adds a second problem
When a bore is scrapped, shops weld it up and re-cut. The heat-affected zone on the alloy is not the same material anymore. You get a hardness step and a corrosion path, and the customer rejects the part at final inspection.
How we hold the numbers
Machining the alloy to drawing, not to feel
Cutting parameters are set from the heat lot, not from a generic nickel-alloy chart.
Cutting strategy
Rough hard, finish light, never rub
The alloy work-hardens the moment the tool rubs instead of cuts. We keep the chip load high enough to stay under the hardened layer and take the finishing pass with a fresh edge at a shallow depth. On a 200 mm tubesheet, that is roughing at 60–80 m/min with coated carbide and a 0.3 mm finishing allowance.
Coolant goes through the tool at high pressure, not over the top. Heat leaves with the chip. When the part has deep pockets or long bores, we switch to through-spindle coolant and peck only when the chip evacuation demands it.
- 1RoughingCoated carbide, high feed per tooth, 0.3 mm left for finish
- 2FinishingFresh edge, shallow depth, Ra 0.8–1.6 μm on sealing faces
- 3CoolantThrough-tool high pressure to pull heat out of the cut
Fixturing
Support the wall before the tool arrives
Thin sections fail in the fixture, not in the cut. We build soft jaws or a dedicated nest that matches the finished contour, so clamping pressure spreads over the whole surface. For rings and liners under 3 mm wall, we back the part with a low-melt or machinable support and cut the support away in the last operation.
Every setup is probed before the first chip. Datum surfaces are cut in the same operation as the features they control, which keeps the stack-up inside ±0.005 mm on the holes that mate with the assembly.
- 1Soft jaws and nestsClamping pressure spread across the finished contour
- 2In-process probingDatum checked before each operation, not after
- 3Single-setup featuresMating holes cut in one operation to protect the stack-up
Material selection
N08800 against the neighbors
Pick from the service conditions, not from the alloy name.
| Grade | Best fit | Watch out for |
|---|---|---|
| Incoloy 800 (N08800) | Furnace parts to 800 °C, moderate corrosion | Not for chloride pitting service |
| Incoloy 800H (N08810) | Creep-limited service above 800 °C | Higher carbon, harder to weld cleanly |
| Incoloy 825 (N08825) | Sulfuric and phosphoric acid duty | More costly per kilogram |
| 316L stainless | General corrosion, lower temperature | Loses strength fast above 600 °C |
What we machine
Part families we run in this alloy
One-off prototypes through 10,000-piece runs, same process control.
01
Heat exchanger tubesheets
Tube hole patterns drilled and reamed to ±0.005 mm, groove and land faces turned in the same setup.
02
Furnace fixtures and trays
Rails, supports and hangers up to 4,000 mm long, machined on the large-travel 5-axis centers.
03
Combustor and burner liners
Thin-wall cylinders with cooling holes, held in a nest to stop distortion.
04
Valve bodies and flanges
Sealing faces finished to Ra 0.8–1.6 μm, bolt patterns positional to the bore.
05
Thermowell and sensor housings
Deep bores and threads in one setup, wall thickness checked on the CMM.
06
Pump and process shafts
Turned on mill-turn centers, keyways and splines cut without re-chucking.
Capability
Machine range for this alloy
Pick the envelope that fits your part; we route it accordingly.
| Machine group | Travel / size | Typical part |
|---|---|---|
| Large 5-axis | 4,000 × 400 × 150 mm | Furnace rails, long trays |
| Medium 5-axis | 750 × 1,150 × 550 mm | Tubesheets, housings |
| Compact 5-axis | 500 × 500 × 450 mm | Liners, small flanges |
| Mill-turn | Ø400 mm rotary table | Shafts, valve bodies |
| 3-axis | 500 × 310 × 200 mm | Plates, brackets, covers |
Why GreatLight
What you get on the purchase order
15Y
Nickel-alloy experience
Machining heat-resistant alloys since 2011, with parameters kept per heat lot rather than per alloy name.
±0.005
Tolerance in millimeters
Held on mating bores and tube hole patterns, verified on the CMM before the part leaves the floor.
127
CNC machines on site
16 simultaneous 5-axis centers, 12 four-axis mills, 16 mill-turn centers. Routing is chosen by geometry.
100%
Inspection before shipment
Raw material check, in-process probing, final inspection. Reports on request.
12 h
Quote with DFM
Quotation and a free DFM analysis inside 12 hours of receiving your drawings.
0
Minimum order quantity
From a single prototype to 10,000+ part runs, no setup charge hidden in the price.
7,600 m²Manufacturing space
3Wholly-owned plants
150Technicians on staff
<2%Historical late-delivery rate
Industry fit
Where these parts end up
Industrial machinery
Furnace trays and radiant-tube supports that hold shape through thermal cycling.
- 4,000 mm max
- Ra 1.6–3.2 μm
- 100% inspection
New energy
Heat exchanger tubesheets and process manifolds for high-temperature loops.
- ±0.005 mm
- ISO 9001:2015
- CMM reports
Aerospace ground hardware
Brackets and duct sections near engine bleed air, where creep matters more than strength.
- 5-axis
- IATF 16949
- 3–5 day ship
FAQs
Questions engineers ask before ordering
Can you machine Incoloy 800 UNS N08800 from my 3D model and 2D drawing?
Yes. Send STEP or IGES plus the drawing with tolerances and finish callouts. We return a DFM analysis with the quote, usually inside 12 hours.
If a feature cannot be held on our machines, we say so before the order rather than after the first article.
What tolerance can you actually hold on this alloy?
±0.005 mm on bores, tube hole patterns and mating faces. That is the practical limit once you account for thermal growth during cutting and spring-back after release.
Looser callouts like ±0.05 mm are cheaper and faster. We will tell you which features need the tight number and which do not.
How do you stop thin walls from distorting?
We fixture to the finished contour with soft jaws or a dedicated nest, and back walls under 3 mm with a machinable support that is cut away last.
Roughing and finishing are separated by a stress-relief pause on parts where the stock removal is heavy.
Do you weld and machine Incoloy 800 assemblies?
We machine the components and can handle light weld prep and post-weld clean-up. Fill passes on pressure-retaining joints are better done by a coded welding shop.
If you need weld-in bosses or flanges located after welding, we machine the mating surfaces after the weld so the final geometry is set on the finished assembly.
What surface finishes are available?
As-machined is Ra 1.6–3.2 μm. Sealing faces and bores come in at Ra 0.8–1.6 μm, and fine finishes down to Ra 0.2–0.8 μm are available where the drawing calls for them.
Bead blasting and tumbling are the common post-machining steps for this alloy. Plating is uncommon because it changes the corrosion behavior.
How do you handle traceability?
We record the heat lot on the raw material certificate and keep it tied to the job number through inspection. Mill certificates are supplied with the parts on request.
Uploads stay confidential, and an NDA is available before you send drawings.
What lead time should I plan for?
Quotation and DFM inside 12 hours, production start within 24 hours of a released order, and parts ship in 3–5 days for typical quantities.
Large 5-axis work and thin-wall parts with multiple stress-relief steps take longer. We give the real number with the quote.
Can you run one prototype and then the production batch?
Yes. There is no minimum order quantity. The prototype is machined on the same machines and inspected against the same criteria as the production run.
Keeping the prototype and the batch on one process means the first article you approve is the part you get at volume.
Send your Incoloy 800 drawings
Upload the model and drawing. You get a quote, a DFM note and a routing plan within 12 hours.
12-hour quote100% inspectionNo MOQNDA on request
