Inconel 625 (N06625) machined parts for seawater-facing marine hardware. We cut pump shafts, valve bodies and heat exchanger fittings on 5-axis centers to ±0.005 mm, with 100% inspection before shipment.
These are the four problems we see most often on seawater-side hardware.
Pitting starts at a machined surface that was left torn. A shaft with pull-out burrs on the seal journal opens a crevice where chloride collects. The seal face then scores, the pump leaks, and the whole assembly comes off the vessel.
This alloy work-hardens fast. A dull insert rubs instead of cutting, the thread flank tears, and two mating parts cold-weld on the second disassembly. The joint is scrap, and the schedule slips by weeks.
Tube sheet holes drilled with the wrong feed leave a tapered bore. The rolled tube does not seat evenly, so the joint weeps under thermal cycling. You find it during a pressure test, not before.
Without a mill certificate and a PMI check, grade substitution is easy to hide. A 316 part in a seawater line corrodes in months, and the paperwork never shows why. We test and document every heat.
Two process controls decide whether a marine part survives its first dry-dock.
Inconel 625 keeps its strength at red heat, which is exactly why it resists seawater and exactly why it is hard to cut. The heat goes into the tool edge, not the chip. We run carbide at surface speeds well below what you would use on 316 stainless, with high-pressure coolant aimed at the insert tip.
That combination keeps the machined skin free of the white layer and micro-cracks that turn into pitting sites. On seal journals and valve seats we then hold Ra 0.8–1.6 μm, which gives chloride fewer places to sit.
Marine hardware rarely arrives as a simple turned part. A valve body has an angled port, a cross-drilled bore and a face that must sit flat against a gasket. Re-fixturing that part three times adds stack-up error and adds handling marks.
We set up on 16 simultaneous 5-axis machining centers, with a Ø400 mm rotary table for parts that need one continuous cut around a bore. Positional work on the 4-axis mills covers the rest. Maximum processing size is 4,000 mm, so long shafts and large housings stay on one machine.
Use this to decide when the alloy price is justified.
| Condition | Inconel 625 (N06625) | 316L stainless |
|---|---|---|
| Flowing seawater, chlorides | Preferred, resists pitting and crevice attack | Corrodes over time |
| Temperature cycling with seawater | Stable to high temperature | Scales and loses strength |
| Static bracket, dry side | Over-specified for the job | Adequate and cheaper |
| Shaft needing high torque | Good strength, galling risk at threads | Softer, wears at the seal |
| Welded fabrication | Weldable without post-heat treatment | Weldable, sensitization risk |
| Lead time and cost | Higher material cost, slower cutting | Lower cost, fast machining |
One shop for the metal cutting, the finishing and the paperwork.
Simultaneous 5-axis cutting for valve bodies, housings and impellers. One setup for features that would otherwise need three.
Shafts, sleeves, bushings and threaded fittings turned on mill-turn centers with live tooling for cross holes.
Flanges, cover plates and mounting blocks, with counterbores and bolt patterns held to drawing.
Single Inconel 625 pieces for fit checks and flow testing before you commit to a production run.
Bead blasting, electroless nickel or passivation to set the surface condition the drawing calls for.
Raw material check, in-process monitoring and final inspection. Dimensional reports on request.
Numbers our process planners work to.
| Item | Capability |
|---|---|
| Material | Inconel 625 (N06625), also Inconel and titanium grades |
| Tolerance | ±0.005 mm (±0.0002 in) on critical features |
| Surface finish | Ra 0.2–0.8 μm fine, Ra 0.8–1.6 μm high, Ra 1.6–3.2 μm as machined |
| Maximum processing size | 4,000 mm |
| Large travel | 4,000 × 400 × 150 mm |
| Medium travel | 750 × 1,150 × 550 mm and 600 × 600 × 600 mm |
| Rotary table | Ø400 mm |
| Batch size | From one prototype to 10,000+ part runs |
| Inspection | 100% before shipment, reports on request |
| Certifications | ISO 9001:2015, IATF 16949:2016, ISO 13485:2016, ISO 27001:2022 |
Six reasons that show up on the purchase order.
15 years cutting hard alloys, with 150 technicians across 3 wholly-owned plants in Dongguan and Singapore.
Critical bores and faces held to ±0.005 mm, checked with calibrated instruments before the part leaves the floor.
16 simultaneous 5-axis centers, 12 four-axis mills, 27 three-axis machines and 16 mill-turn centers.
Quotation and free DFM analysis within 12 hours. Production can start within 24 hours of approval.
Parts ship in 3–5 days on standard jobs. Historical late-delivery probability is below 2%.
Every part inspected before shipment, with material certificates and dimensional reports available.
No minimum order quantity. A single prototype and a 10,000-piece run go through the same inspection.
Uploads stay secure and confidential. A non-disclosure agreement is available on request.
Turned and ground on mill-turn centers with live tooling for keyways.
Angled ports and cross bores cut in one 5-axis setup.
Tube sheet holes, flanges and baffle plates held to drawing.
Threaded connectors, adapters and mounting blocks.
The deciding factor is chloride exposure. Inconel 625 (N06625) resists pitting and crevice corrosion in flowing seawater, and it keeps its strength when the part also sees heat, as in a heat exchanger or near an exhaust run.
If the part sits on the dry side, carries no load and never sees spray, 316L does the job for less money. We will say so instead of quoting the expensive alloy.
Yes. We hold Ra 0.2–0.8 μm on fine finishes and Ra 0.8–1.6 μm on standard sealing faces. Both require light finishing passes with sharp tooling and no dwell on the surface.
The reason to spend on finish is pitting. A torn surface gives chloride a place to start. On a seal journal, that decides how long the pump runs between rebuilds.
Maximum processing size is 4,000 mm. On large travel we work to 4,000 × 400 × 150 mm, and on medium travel to 750 × 1,150 × 550 mm or 600 × 600 × 600 mm.
Long shafts go on machines with steady rest support. If your part is longer than 4,000 mm, send the drawing and we will tell you whether we can hold it.
Galling comes from rubbing, not from the alloy itself. We use sharp, correctly ground thread inserts, control the cutting speed, and avoid re-cutting a thread that has already work-hardened.
On mating pairs we can also specify a surface treatment or a controlled thread class. If the assembly will be taken apart in service, tell us and we will plan for it.
Yes. Every job starts with a raw material check against the mill certificate. We can add a positive material identification check on request.
Without that step, grade substitution is easy to hide. A part that should be N06625 and is not will fail in service, and the paperwork will not explain why.
One piece. There is no minimum order quantity. A single prototype for a fit check and a 10,000-piece production run go through the same setup and inspection discipline.
Prototypes usually ship in 3–5 days. Larger runs are scheduled after the DFM review, and we confirm the dates before cutting metal.
Within 12 hours. Send the 3D model or a 2D drawing with tolerances, and we return a quotation plus a free DFM analysis pointing out features that will drive cost or risk.
If the design needs a change, better to hear it before the first setup than after the parts are on the bench.
Yes. Uploads are kept secure and confidential, and we sign a non-disclosure agreement on request.
Marine designs often carry a customer's own geometry and performance data. We treat drawings, models and test results as the buyer's property.
Upload the model or drawing and we return a quotation with a free DFM analysis within 12 hours.
12-hour quote100% inspectionAny batch sizeNDA on request
Trusted by engineers and manufacturers worldwide
Upload your 3D model or 2D drawing and get a quotation with a free DFM analysis. Maximum processing size 4,000 mm.
CNC Metals 13 grades
CNC Plastics 10 grades
Machines & processes 12 options
Surface & post-processing 10 options
Material: not selected Machine: not selected Post-process: not selected
Fill in this short form and we'll open WhatsApp with your message ready to send. We only use these details to reply to you.
Nothing is sent until you press send inside WhatsApp.
