Flanges and machined rings
Identify the sealing face, bore and bolt circle on the drawing. Include gasket details and the inspection requirements for any pressure-retaining design.
Inconel flanges, shafts, sleeves and housings
4 part examples
Stepped shafts and threaded stems
Specify the mating diameters, shoulders, thread form and reference axis. Mark where runout, surface finish or thread inspection affects the assembly.
Sleeves, spacers and bushings
Show wall thickness, bore depth and the final fit. Tell us whether dimensions apply before or after any heat treatment, coating or finish machining.
Milled housings and multi-face blocks
Send the model with pocket depths, port locations and datum relationships. Identify intersecting passages, trapped burrs and features that need inspection access.
Inconel 625, 718 and 600 compared
Inconel 625
UNS N06625
A nickel-chromium alloy strengthened mainly by molybdenum and niobium in solid solution. It is used where strength and corrosion resistance matter together. [1]
- Material details to confirm
- We select the machining route around the supplied condition. Annealed and solution-treated 625 have different mechanical properties; the condition stays tied to the part’s service requirement and product specification.
- Include with the drawing
- State the process fluid, temperature and any approved-source restrictions.
Inconel 718
UNS N07718
An age-hardenable nickel alloy. The specified heat treatment is part of the requirement, not an optional finishing detail. [2]
- Material details to confirm
- Distinguish the material condition at machining from the condition required at delivery.
- Include with the drawing
- Include the heat-treatment specification, required records and final acceptance criteria.
Inconel 600
UNS N06600
A nickel-chromium-iron alloy used for heat and corrosion resistance. It is not precipitation-hardened in the same way as alloy 718. [3]
- Material details to confirm
- Confirm the product form, supplied condition and intended service environment.
- Include with the drawing
- Do not substitute another nickel alloy based only on a similar trade name.
625 and 718: grade and delivery condition
For a drawing that specifies 625: carry the grade, product form and condition through the quote. Its corrosion-related uses do not make it a universal replacement for other alloys. [1]
For a drawing that specifies 718: clarify whether stock is supplied solution-treated or already aged, and which final properties must be documented. [2]
For other Inconel grades, provide the material specification and required condition for review.
| Property | Annealed Special Metals alloy 625 | Solution-treated |
|---|---|---|
| Tensile strength (MPa) | 827–1,034 | 724–896 |
| 0.2% yield strength (MPa) | 414–655 | 290–414 |
| Brinell hardness (HB) | 145–220 | 116–194 |
Special Metals nominal room-temperature ranges for rod, bar and plate sizes up to 4 in (101.6 mm). Annealed stock has higher strength and hardness in this dataset; solution-treated stock is selected when optimum creep and rupture resistance governs. Procurement limits follow the specified product standard and material condition.
Confirm the material condition before machining
Write down the incoming and final conditions
A quote should distinguish the material being purchased from the part you expect to receive. Include the stock form, product standard and edition, heat-treatment condition, and any required mechanical-property or hardness records.
Keep heat treatment in the manufacturing plan
For age-hardenable alloy 718, the selected treatment affects the material properties. Agree which operations occur before treatment, which dimensions are finished afterward, and when final inspection takes place. [2]
Alloy-specific heat treatment
A 718 aging schedule is not a general treatment for every Inconel grade. Use the treatment specified for the actual alloy and application, with any proposed change approved before production. [1][3]
No delivery condition selected.
Milling, turning and drilling nickel-alloy parts
Turning for bores, shoulders and sealing faces
Rotational features need a defined datum axis and an agreed order of operations. Describe the critical fits, surface-finish callouts and any restrictions on workholding marks. Include the drawing even when a 3D model is available.
Milling for pockets and features on several faces
Tool reach, clamping and measurement access determine the setup plan. Multi-axis machining may provide access to angled features; the geometry determines the number and type of setups.
Drilling and threading with chip access in mind
Show drilled depth separately from usable thread depth. For crossing holes and internal ports, identify where burrs must be removed and whether borescope, leak or other application-specific checks are required.
Inconel tolerances after heat treatment and finishing
| Feature | Specification | Acceptance condition | Verification |
|---|---|---|---|
| Diameters and fits | Mating feature; fit; datum axis | After specified final operations | Specified measurements or gauges |
| Position and runout | Datums; controlled hole pattern/rotating feature | Datum-referenced measurement setup | Required geometric features reported |
| Sealing and contact faces | Flatness; roughness parameter/units; prohibited marks | Drawing-specified functional surfaces | Dimensional and surface checks, including roughness |
| Threads and internal passages | Thread form/pitch/class; effective depth; burr removal | Accessible, intersecting or hidden features identified | Thread checks; specified internal-feature verification |
| Post-treatment dimensions | Delivery condition; final treated/coated dimensions | Specified final condition | Final dimensions; separate required process records |
There is no single tolerance that applies to every Inconel part. Size, geometry, condition, access and the inspection method are reviewed before a tolerance is accepted.
Design details that affect machining and inspection
Leave access for the tool and the probe
Internal corners, angled bores and deep pockets should be reviewed for both cutting and measurement. Mark any geometry that cannot change, so possible design adjustments stay separate from mandatory features.
Support thin walls and long features
Identify thin sections, slender stems and large pockets early. Ask how the component can be held without interfering with finished faces, and whether a trial sample is needed before releasing the full quantity.
Edge conditions for sealing ports and passages
“Deburr all edges” may not be enough for a sealing port, flow passage or close-fit shoulder. Put the required edge condition, no-break edges and inspection access on the drawing.
Control changes to the released design
Send the model and drawing at the same revision. A suggested corner radius, alternate stock size or changed process route is a proposal for approval—not permission to alter your part.
Discuss critical Inconel features
No review topics selected.
Surface finishes for machined Inconel parts
As machined
Keep the functional surface-texture callouts, permitted tool marks and edge requirements on the drawing. An uncoated part still needs an agreed cleaning and handling method.
Ground / lapped as specified
Name the feature and the required final size, flatness or texture. Grinding or lapping is an order-specific secondary operation, not assumed for every part.
Specified cleaning / descaling
Provide the applicable process and acceptance requirements where oxide or contamination removal is necessary. Agree how treated surfaces and dimensions will be checked.
Drawing-specified coating
Supply the coating specification, thickness, masking and final-size requirements. Any qualified-source requirement must be identified before the process is quoted.
Specify heat treatment, cleaning, coatings and final machining separately in the quotation.
Inspection records tied to the material heat
Link the material certificate to the actual stock
Ask for the records your order requires: the material designation, product specification, supplied condition and heat or lot identification. State any mill, country-of-origin or approved-source restriction before material is ordered.
Separate material, process and part inspection records
A dimensional report does not replace a heat-treatment record, and a material certificate does not show that the finished geometry passes. Identify which records you need and how they should refer back to the order.
Define specialist tests before pricing the part
For non-destructive testing, positive material identification, pressure testing or other special checks, provide the method, acceptance criteria, sampling and provider requirements. Availability and responsibility are confirmed in the quote.
Specify the application as well as the alloy
Process equipment components
For valve, pump or instrument parts, include the medium, concentration, temperature and pressure. Material selection and pressure-design approval remain separate from machining acceptance.
Thermal equipment and engine hardware
State the duty cycle, operating environment and any drawing-controlled source or qualification requirement. General alloy information is not a qualification for a particular engine or safety-critical component.
Customer-designed mechanical assemblies
Mating parts and assembly-controlling features define requirements for rings, shafts, sleeves and brackets. Approved drawings provide the manufacturing reference.
What affects the cost of Inconel machining?
Material and starting condition
Compare quotes against the same grade, product form and supplied condition. Include any approved-source requirement and the records needed with the stock; a lower raw-material price may cover a different scope.
Metal removal and secondary operations
Stock allowance, deep features, tool access and separate setups affect the manufacturing plan. Nickel-alloy cutting conditions and tool wear also matter when estimating the work. [4]
Samples, tests and repeat quantities
Ask for sample and batch quantities to be priced separately where useful. Include heat treatment, finishing, specialist tests, packing and required documentation so you can compare complete quotations.
How we handle an Inconel machining order
Review the released drawing
Send the CAD model, drawing, material specification and order quantities. Identify critical features and any source or inspection restrictions.
Agree the route and records
Confirm material responsibility, manufacturing scope, treatment sequence and acceptance criteria. Resolve proposed changes before releasing production.
Approve samples when required
Define the sample quantity and what needs approval. Keep sample acceptance separate from any further application or qualification testing.
Inspect, pack and control revisions
Agree the final report, part identification and packing. Repeat orders should reference the approved revision and any authorized process changes.
Questions about Inconel CNC machining
What information do you need for an Inconel machining quote?
Send a matching CAD model and dimensioned drawing, grade and product specification, supplied and required delivery conditions, quantity, finish and inspection requirements. Include the application and any approved-source restrictions that affect procurement.
What is the difference between Inconel 625 and 718?
Alloy 625 derives its principal strengthening from solid solution, while 718 is age-hardenable. They are not interchangeable by name or by a single strength value; use the grade and condition specified for the application. [1][2]
Do I need to specify the heat-treatment condition?
Yes. State both the incoming stock condition and the required condition at delivery. Where treatment or property testing is required, include the specification and records, then agree the sequence of machining and final inspection.
Can Inconel parts be CNC milled and turned?
A component may need turning, milling, drilling, threading or several operations. Send the geometry and material condition for review; the proposed route depends on tool access, workholding and the features that must be inspected.
What tolerances can VETCNC quote for an Inconel part?
Tolerance acceptance is drawing-specific. The review considers part size, shape, material condition, treatment sequence and measurement access. Mark critical fits and datums rather than relying on one tolerance for the entire component.
Can you review customer-supplied Inconel stock?
Yes, it can be discussed. Share the material certificate, stock dimensions, condition and available allowance. Acceptance, traceability, remaining tests and responsibility for supplied material must be agreed before it is machined.
Are 625, 718 and 600 always available from stock?
This page is not an inventory list. The exact product form, size, condition, source and documentation are checked for each inquiry. Any suggested substitute requires your approval before material is ordered.
Can I request material certificates and test reports?
Include the records you require with the inquiry. Material certificates, heat-treatment records, dimensional reports and specialist test reports cover different things. Their scope, provider and link to the order must be agreed separately.
Does an Inconel grade make a part approved for aerospace or pressure service?
No application approval is implied by the grade name or these illustrations. The drawing authority or customer must identify the applicable design, qualification, material-source and process requirements; acceptance of that scope needs specific confirmation.
Why does the machining condition affect the quote?
The alloy’s supplied condition affects machining behavior. Nickel-based superalloys can also present work-hardening, heat and tool-wear challenges, so quotes should use the same material condition and manufacturing scope. [4]
Can I order a prototype before a production batch?
Discuss the sample quantity and the purpose of the trial—fit, dimensional verification or process approval, for example. Specify any condition or inspection requirements that must already apply to the prototype.
How will I know who is manufacturing the parts?
The proposed scope should identify whether work is handled by our factories or an agreed partner, including any outside treatment or specialist test. We can also discuss a direct introduction when that arrangement suits your project.
Request a quote for your Inconel parts
- Matching CAD model and dimensioned drawing
- Grade, product specification, stock form and incoming condition
- Required delivery condition, heat treatment and process records
- Critical fits, surface requirements, tests and source restrictions
- Sample and batch quantities, approvals and requested arrival date
Agree confidentiality and the transfer method before sharing sensitive or restricted files.
PROJECT SUPPORT
Discuss your Inconel part
Share your drawing, alloy condition and quantity. Specify whether you will supply the material or need material sourcing, with the required traceability records.
Material References
- Special Metals — INCONEL alloy 625 technical bulletin — Alloy identity, solid-solution strengthening and general applications.
- Special Metals — INCONEL alloy 718 technical bulletin — Alloy identity, age hardening and the importance of heat-treatment condition.
- Special Metals — INCONEL alloy 600 technical bulletin — Alloy identity and non-precipitation-hardening behavior.
- Sandvik Coromant — Workpiece materials — Machining behavior of heat-resistant superalloys and the role of material condition.
- ISCAR — Superalloy machining — Cutting-edge and process considerations for superalloy machining.
References for alloy properties and machining. INCONEL is a trademark of the Special Metals Corporation group of companies. Procurement must follow the approved grade, product specification and source requirements.
