01
Tool wear eats the tolerance
This alloy work-hardens the moment the insert rubs instead of cuts. Tool life drops, the last 20 parts of a run drift 0.02 mm, and the whole lot needs rework or scrap.
Nickel Alloy Machining
Inconel 718 N07718 CNC Machining
We turn and mill nickel alloy N07718 into downhole tools, wellhead bodies, valve stems and pump hardware. Tight tolerances hold on tough cuts, and every part is measured before it ships.
Ø400 mm rotary table±0.005 mmRa 0.8–1.6 μmSolution treated + agedFrom one prototype12-hour quote
16Simultaneous 5-axis centers
127High-precision CNC machines
±0.005 mmAchievable tolerance
99.99%Qualification rate
Where Inconel jobs go wrong
Four failures that show up after the chips are cleared
02
Built-up edge on gummy cuts
Too low a surface speed and the material smears onto the insert. Flank wear jumps, surface finish goes past Ra 3.2 μm, and a sealing face leaks on the test bench.
03
Heat that moves the part
Roughing a 300 mm wellhead body puts a lot of heat into the wall. Measure it hot and the bore looks right. Measure it cold and it is out of round.
04
Threads that gall on assembly
Galling starts at the thread flank, not the crest. A rolled thread with the wrong pitch diameter will still pass a go gauge, then seize on the third make-up.
How we run the job
Machining N07718 without giving away the tolerance
Toolpath, coolant and insert grade are chosen for the alloy, not copied from a stainless program.
Roughing and finishing
Separate the roughing heat from the finishing cut
Nickel alloys keep their strength at 700 °C, so the heat goes into the tool and the part instead of the chip. We rough with high-feed cutters at conservative surface speed, then let the part equalize before the finishing pass. That pause is what keeps a 300 mm bore round.
Finishing runs on positive-rake carbide or ceramic inserts at 30–45 m/min. Depth of cut stays above the work-hardened layer left by the previous pass, so the next insert cuts clean material rather than a hard skin.
- 1Climb milling on all finishing passesLess rubbing, longer insert life, better Ra.
- 2High-pressure coolant through the toolBreaks the chip and pulls heat out of the cutting zone.
- 3Rough, cool, then finishWall thickness stays stable on thin downhole housings.
Geometry and access
Five axes reach the ports a three-axis job cannot
Valve bodies and manifold blocks carry angled ports, cross holes and sealing faces that sit off every primary axis. Turning the part across a trunnion lets us cut those features in one setup instead of four, which removes three chances to stack up position error.
A Ø400 mm rotary table with 16 simultaneous 5-axis centers covers parts up to 4,000 mm long. For long shafts and mandrels we use mill-turn centers so the part stays in one chuck through turning, milling and drilling.
- 1One setup for angled portsPosition error does not accumulate across four fixtures.
- 2Mill-turn for long shaftsTurning and milling without re-chucking the part.
- 34,000 mm maximum part lengthDownhole housings fit inside the work envelope.
Selection guide
When N07718 is the right call, and when it is not
Match the alloy to the service condition before the drawing is released.
| Service condition | N07718 fits | Look elsewhere |
|---|---|---|
| Sour gas with H₂S | Aged condition, hardness checked | Carbon steel without a barrier |
| Continuous 650 °C | Yes, up to about 700 °C | Aluminum or 17-4PH |
| Seawater plus chlorides | Yes, with correct aging | 303 stainless |
| Deep cryogenic service | Marginal, check impact data | Austenitic grades at 316L |
| Weight-critical airframe | Often too heavy | Titanium Ti-6Al-4V |
| Cost-driven bracket | Over-specified | 6061-T6 or 4140 |
What we make
Part families we machine from N07718 bar and forgings
01
Downhole tool bodies
Housings, subs and mandrels with deep bores and cross ports. OD and ID turned in one setup where the length allows.
02
Wellhead components
Bonnet bodies, adapter flanges and studded outlets. Sealing faces held to Ra 0.8–1.6 μm for metal-to-metal contact.
03
Valve stems and seats
Stems, plugs, seat rings and trim. Threads turned or rolled to the specified pitch diameter, not just the go gauge.
04
Pump and compressor parts
Impellers, wear rings and sleeves. Balance-critical diameters held on the same datum through every operation.
05
Fasteners and studs
Large-diameter studs, nuts and bolting for flanged joints. Rolled threads on request for fatigue life.
06
Instrumentation fittings
Sensor housings, gauge adapters and small manifolds. Small parts run at the same tolerance as the big ones.
Capability envelope
Tolerances, sizes and finishes we quote against
| Parameter | Capability | Notes |
|---|---|---|
| Tolerance | ±0.005 mm (±0.0002 in) | Achievable on turned diameters |
| Surface finish | Ra 0.2–0.8 μm | Fine finish on sealing faces |
| Standard finish | Ra 1.6–3.2 μm | As-machined on general surfaces |
| Max part length | 4,000 mm | Long shafts and housings |
| Rotary table | Ø400 mm | Angled ports and cross holes |
| Machines | 127 CNC, 16 five-axis | Milling, turning and mill-turn |
| Order size | 1 to 10,000+ parts | Prototype through production |
| Lead time | 3–5 days | After drawing and material release |
Why GreatLight
Numbers behind the quote
15Y
Machining since 2011
Fifteen years on nickel alloys and stainless. The insert grades and speeds are already dialed in, so the first part is not a test cut.
±0.005
Tolerance on turned diameters
Held on production runs, not just on the first article. Gauge repeatability is checked before the run starts.
99.99%
Qualification rate
Parts that pass final inspection against the drawing. Measured with calibrated instruments and recorded.
12h
Quote and DFM turnaround
Drawing review with a manufacturability note back to you inside 12 hours. Production can start within 24 hours.
150
Technicians on staff
Programmers, setup machinists and inspectors in three wholly-owned plants across 7,600 m².
100%
Inspection before shipment
Raw material check, in-process monitoring, final inspection. Reports on request.
7,600 m²Manufacturing space
3Wholly-owned plants
<2%Historical late-delivery rate
ISO 9001IATF 16949 · ISO 13485
Industry requirements
What these sectors ask for, and what we hand over
Oil and gas
Sour service parts need hardness control after aging and a record of it.
- Aged condition
- Hardness report
- ±0.005 mm
Power generation
High-temperature seals and stems need a finish that holds at 650 °C.
- Ra 0.8–1.6 μm
- 5-axis ports
- 100% inspection
New energy
High-pressure manifolds need angled ports on a single datum.
- One setup
- Ø400 mm table
- Leak-tight faces
Industrial machinery
Wear parts in abrasive service need consistent wall thickness run to run.
- 4,000 mm length
- ±0.005 mm
- Batch traceability
FAQs
Questions engineers ask before releasing the drawing
Can you machine N07718 in the aged condition?
Yes. Aging takes the alloy to roughly 40 HRC, so carbide still cuts it but tool life shortens. We adjust speeds and change inserts on a fixed count rather than waiting for wear.
If the geometry is simple, machining before aging and finishing after is often cheaper. Send both versions and we will say which one holds tolerance better.
How do you control work hardening?
Depth of cut stays above the hardened layer from the previous pass. A finishing pass that only skims 0.05 mm is cutting the hardest material in the part.
Coolant goes through the tool at high pressure. It breaks the chip and keeps the cutting zone from building heat between passes.
What tolerance can you actually hold on a long bore?
±0.005 mm on turned diameters is our standard capability. On a bore longer than 5× diameter, the limiting factor is usually the boring bar, not the machine.
We rough, let the part cool to room temperature, then finish. Measuring hot is how a bore ends up undersized after it sits overnight.
Do you supply material, or can we send ours?
Both work. We buy N07718 bar and forgings against the specification and heat number you list, and we keep the mill certificate with the job.
Customer-supplied stock is fine. We check the heat number and dimensions on arrival and flag anything that will not clean up.
How do you handle threads on N07718?
Threads are turned or rolled to the specified pitch diameter, not just checked with a go gauge. Galling starts at the flank, and pitch diameter is what drives it.
For API threads we cut to the drawing profile and record the measurements on the inspection sheet.
What surface finishes are available?
As-machined runs Ra 1.6–3.2 μm. Sealing faces and stem surfaces get Ra 0.8–1.6 μm, and fine finish down to Ra 0.2–0.8 μm is available where the drawing calls for it.
Bead blasting, passivation and laser marking are done in-house. Marking needs a minimum character height of 1.5 mm.
Can you run one prototype before production?
Yes. There is no minimum order quantity, so a single part and a 10,000-part run go through the same process.
The prototype gives us real cutting data. If the production run needs a fixture or a different toolpath, we change it before the batch starts.
How is confidentiality handled?
Uploads are secure, and we can sign an NDA before you send the drawing. The agreement is available on request.
Programs and drawings stay inside the job file. They are not shared outside the plants.
Send the drawing, get a quote in 12 hours
Upload a STEP file or a PDF with tolerances. An engineer reviews it for manufacturability and comes back with a price, a lead time and a note on anything that will not cut clean.
12-hour quote and DFM100% inspectionNo minimum orderNDA on request
