CNC Cylindrical Grinding 40Cr Steel from VT machining delivers precision 40Cr Steel parts made to your exact drawing. Cylindrical grinding finishes outer diameters of rotational parts to precise size and roundness, with parameters tuned to 40Cr Steel, which is strong, economical and widely available.
CNC Cylindrical Grinding Capability for 40Cr Steel
- Carbon/low-alloy grades
- Economical & weldable
- Tolerance to ±0.02 mm
- Hardenable by heat treat
40Cr Steel Material Data
| Density | 7.85 g/cm³ |
|---|---|
| Tensile strength | 585 MPa |
| Yield strength (0.2%) | 450 MPa |
| Hardness | 170 HB |
| Melting point | 1420–1460 °C |
| Thermal conductivity | 51.9 W/m·K |
| Thermal expansion | 11.5 ×10⁻⁶/K |
| Electrical conductivity | 9% |
| Machinability (C36000 = 100%) | 57% |
| Grades we run | 1018, 1045, 1215, A36, S45C, St37, 4140 (see alloy steel) |
Published typical values for 1045. Other grades in the family differ — the certificate supplied with your order carries the actual heat-lot figures.
Rust. Bare steel flash-rusts within hours in a humid container, so parts are oiled or passivated before packing unless you specify otherwise.
Machining 40Cr Steel with CNC Cylindrical Grinding
The machinability of 40Cr Steel is good to excellent depending on carbon content; free-machining grades cut cleanly. For CNC Cylindrical Grinding we select tooling, feeds, speeds and coolant to match, keeping the 40Cr Steel workpiece stable and the result accurate.
Because we machine 40Cr Steel regularly, proven settings shorten setup and keep quality repeatable across reorders.
Achievable Tolerances for CNC Cylindrical Grinding 40Cr Steel
| Feature | Standard | Precision |
|---|---|---|
| Size (OD, ID, thickness) | ±0.005 mm | ±0.002 mm |
| Flatness over 100 mm | 0.010 mm | 0.003 mm |
| Parallelism | 0.010 mm | 0.003 mm |
| Roundness | 0.005 mm | 0.002 mm |
| Squareness | 0.010 mm | 0.005 mm |
| Surface finish | Ra 0.4 µm | Ra 0.1 µm |
| Workpiece hardness | up to 62 HRC | up to 65 HRC |
Standard is what a normal quotation assumes. Precision is available on nominated features and is priced separately, because it needs extra setups, in-process gauging and CMM verification. Call out only the features that need it — blanket-tightening a drawing is the single most common reason a quote comes back expensive.
CNC Cylindrical Grinding Tolerances & Surface Finish
Ground 40Cr Steel reaches single-micron tolerances on size, flatness and parallelism, with surface finishes down to Ra 0.1–0.4 µm — and a near-mirror finish on suitable alloys.
The tightest tolerances are reserved for the features your drawing flags as critical. Share your tolerance scheme and we will confirm what is realistic before quoting.
Why 40Cr Steel?
Specifying 40Cr Steel for CNC Cylindrical Grinding 40Cr Steel is usually about its properties: strong, economical and widely available. Tell us the condition you need and we machine to it.
CNC Cylindrical Grinding Quality & Inspection
Consistent quality comes from disciplined process control. Critical dimensions on 40Cr Steel parts are checked in-process and verified at final inspection using calibrated instruments and, where required, CMM measurement. Full documentation — dimensional reports, mill certs, FAIR — is available when your programme needs it.
Design Tips for CNC Cylindrical Grinding 40Cr Steel
A few design choices make a real difference to cost and quality. Allowing adequate grind stock, specifying realistic flatness over the true datum, and relieving corners help us hit tight tolerances on 40Cr Steel efficiently. If you send your model early, we will return practical DFM feedback before you commit to production.
Secondary Operations & Finishing
We complete 40Cr Steel components with the secondary steps your drawing calls for. We arrange heat treatment, surface treatment, marking and assembly as needed. Tell us the final spec and we will plan the full route so parts arrive ready to use.
Applications of CNC Cylindrical Grinding 40Cr Steel
CNC Cylindrical Grinding of 40Cr Steel supports parts across aerospace, medical, automotive, electronics, semiconductor, energy and general industrial sectors. We scale from one-off prototypes to ongoing production while holding the same quality.
How to Order CNC Cylindrical Grinding 40Cr Steel
Ordering 40Cr Steel parts is straightforward. Provide the drawing, material, quantity and any certification needs. Our engineers reply — in English — with feasibility, pricing and a realistic lead time, usually within one business day.
Finishing Options for 40Cr Steel
| Finish | Thickness / effect | Why it gets specified |
|---|---|---|
| Black oxide | 1–2 µm | Mild corrosion resistance, no dimensional change |
| Zinc plate + clear/yellow | 5–12 µm | ASTM B633, general corrosion protection |
| Nickel plate (electroless) | 10–25 µm | Uniform in bores, 500 HV after bake |
| Phosphate | 5–10 µm | Paint key, mild lubricity |
| Powder coat | 60–120 µm | RAL colours |
| Deburr / edge break | 0.05–0.3 mm | All parts unless the drawing says otherwise |
| Bead blast | Ra 1.6–3.2 µm | Uniform matt finish, hides tool marks |
| Laser marking | — | Part number, lot code, data matrix |
No drawing yet? Build one in the browser.
Set the metal, dimensions and features, watch the 3D model update as you type, then switch to the 2D sheet to add dimensions and tolerances. Download it or send it straight to us with your RFQ.
What We Need to Quote CNC Cylindrical Grinding 40Cr Steel
- GeometrySTEP or IGES for the 3D model, plus a PDF drawing if you have tolerance callouts. A dimensioned sketch is enough to start.
- MaterialThe exact 40Cr Steel grade and condition — temper, heat-treat state or hardness. If you are not sure, tell us the function and we will suggest one.
- QuantityPrototype count and the expected annual volume. Both change how the part is made and therefore what it costs.
- TolerancesWhich features are critical. Everything else runs to our standard tolerance, which is what keeps the price sensible.
- FinishSurface treatment, cosmetic requirements, and any faces that must be masked.
- DocumentsWhether you need a material certificate, dimensional report, FAIR or PPAP with the shipment.
Missing something from the list is not a problem — send what you have. We will come back with the specific questions rather than a generic form.
40Cr Steel in Other Processes
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Send the drawing, the 40Cr Steel condition and the quantity — pricing and lead time come back the same or next business day.
Request a QuoteFrequently Asked Questions
What surface finish is achievable on 40Cr Steel with CNC Cylindrical Grinding?
Grinding can take 40Cr Steel to a fine finish — typically Ra 0.1–0.4 µm, and to a mirror grade on suitable alloys.
What is the typical lead time and minimum order for CNC Cylindrical Grinding 40Cr Steel?
CNC Cylindrical Grinding prototypes for 40Cr Steel can be produced quickly and scaled to series production. Send your drawing and quantity and we will advise lead time and any minimum order.
Why is 40Cr Steel a good choice for CNC Cylindrical Grinding?
40Cr Steel is strong, economical and widely available, which makes it well suited to CNC Cylindrical Grinding. We tune the process to the alloy so the finished 40Cr Steel grinding part meets your dimensional and functional requirements.
What tolerances can you hold for CNC Cylindrical Grinding 40Cr Steel?
Achievable tolerances for 40Cr Steel grinding depend on the alloy, geometry and feature size. Grinding routinely holds single-micron tolerances on diameter, flatness and parallelism. Exact figures are confirmed against your drawing callouts.
Which industries use CNC Cylindrical Grinding 40Cr Steel parts?
CNC Cylindrical Grinding 40Cr Steel parts are used across aerospace, medical, automotive, electronics, semiconductor and general industrial sectors — anywhere precise 40Cr Steel components are required.
What is CNC Cylindrical Grinding 40Cr Steel and how is it done?
CNC Cylindrical Grinding 40Cr Steel refers to cylindrical grinding finishes outer diameters of rotational parts to precise size and roundness. Applied to 40Cr Steel — strong, economical and widely available — VT machining produces each part to your CAD drawing, selecting parameters from your tolerance, finish and quantity requirements.