CNC Surface Grinding 8620 Alloy Steel is part of VT machining's grade-specific capability. 8620 Alloy Steel is high-strength and hardenable, and we combine controlled grinding with material-aware setup to produce parts that meet your specification.
CNC Surface Grinding Capability for 8620 Alloy Steel
- Cr-Mo / Ni-Cr-Mo grades
- High strength & hardenability
- Tolerance to ±0.01 mm
- Heat-treatable to 30–55 HRC
8620 Alloy Steel Material Data
| Density | 7.85 g/cm³ |
|---|---|
| Tensile strength | 655–1020 MPa |
| Yield strength (0.2%) | 415–900 MPa |
| Hardness | 197–302 HB |
| Melting point | 1416 °C |
| Thermal conductivity | 42.6 W/m·K |
| Thermal expansion | 12.3 ×10⁻⁶/K |
| Electrical conductivity | 8% |
| Machinability (C36000 = 100%) | 65% (annealed) |
| Grades we run | 4140, 4340, 8620, 20CrMnTi, 42CrMo4, 20MnCr5 |
Published typical values for 4140 (Q&T). Other grades in the family differ — the certificate supplied with your order carries the actual heat-lot figures.
Heat treatment moves the part. Anything held tighter than ±0.02 mm is machined soft, hardened, then ground or hard-turned to final size.
Machining 8620 Alloy Steel with CNC Surface Grinding
8620 Alloy Steel behaves predictably under CNC Surface Grinding once parameters are dialled in: machinability is good in annealed condition; machined soft then heat-treated to final hardness, and we tune the operation accordingly.
We hold reference parameters for this grade, so repeat orders of 8620 Alloy Steel run consistently from one batch to the next.
Achievable Tolerances for CNC Surface Grinding 8620 Alloy 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.
Why 8620 Alloy Steel?
8620 Alloy Steel is chosen when a part needs what this grade offers — it is high-strength and hardenable. We confirm the grade and any temper or heat-treat condition with you before machining.
Design Tips for CNC Surface Grinding 8620 Alloy Steel
We are happy to suggest design tweaks that improve manufacturability. Allowing adequate grind stock, specifying realistic flatness over the true datum, and relieving corners help us hit tight tolerances on 8620 Alloy Steel efficiently. If you send your model early, we will return practical DFM feedback before you commit to production.
Secondary Operations & Finishing
Finished 8620 Alloy Steel parts can move straight into secondary operations under one roof. Typical add-ons are deburring, passivation, anodising, plating, blasting, polishing and laser marking. We coordinate the whole chain so you receive complete, inspection-ready parts.
CNC Surface Grinding Tolerances & Surface Finish
Ground 8620 Alloy 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.
Final tolerances are governed by the material's behaviour, wall thickness and overall stiffness. We give honest DFM feedback if a callout would be costly or better achieved another way.
CNC Surface Grinding Quality & Inspection
We control quality throughout the process, not just at the end. In-process checks plus final inspection — including CMM where specified — keep every 8620 Alloy Steel part to print. Inspection reports, material certificates and first-article documentation can be supplied on request.
Applications of CNC Surface Grinding 8620 Alloy Steel
Customers order CNC Surface Grinding 8620 Alloy Steel components for everything from instrumentation to structural and functional assemblies. Whether you need a single prototype or recurring production volume, the same process discipline applies.
How to Order CNC Surface Grinding 8620 Alloy Steel
Getting a quote is simple. Share your model, the material grade, your quantity and target tolerances. You receive a clear quotation with lead time and honest manufacturability feedback.
Finishing Options for 8620 Alloy Steel
| Finish | Thickness / effect | Why it gets specified |
|---|---|---|
| Through hardening | — | 30–55 HRC, ground afterwards for tight sizes |
| Case hardening (carburise) | 0.3–1.2 mm case | 58–62 HRC surface, tough core |
| Nitride | 0.1–0.5 mm | 900–1100 HV, minimal distortion |
| Black oxide | 1–2 µm | Cosmetic + light corrosion protection |
| Zinc / nickel plate | 5–25 µm | Corrosion protection |
| 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 Surface Grinding 8620 Alloy 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 8620 Alloy 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.
8620 Alloy Steel in Other Processes
Related
Send the drawing, the 8620 Alloy Steel condition and the quantity — pricing and lead time come back the same or next business day.
Request a QuoteFrequently Asked Questions
Why is 8620 Alloy Steel a good choice for CNC Surface Grinding?
8620 Alloy Steel is high-strength and hardenable, which makes it well suited to CNC Surface Grinding. We tune the process to the alloy so the finished 8620 Alloy Steel grinding part meets your dimensional and functional requirements.
Which industries use CNC Surface Grinding 8620 Alloy Steel parts?
CNC Surface Grinding 8620 Alloy Steel parts are used across aerospace, medical, automotive, electronics, semiconductor and general industrial sectors — anywhere precise 8620 Alloy Steel components are required.
Does CNC Surface Grinding 8620 Alloy Steel require dedicated tooling?
Most 8620 Alloy Steel grinding work uses standard cutting tools and CNC programs; dedicated fixtures are made only when geometry or volume requires them.
What surface finish is achievable on 8620 Alloy Steel with CNC Surface Grinding?
Grinding can take 8620 Alloy Steel to a fine finish — typically Ra 0.1–0.4 µm, and to a mirror grade on suitable alloys.
What tolerances can you hold for CNC Surface Grinding 8620 Alloy Steel?
Achievable tolerances for 8620 Alloy 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.