CNC EDM Drilling Alloy Steel from VT machining delivers precision Alloy Steel parts produced to your exact drawing. Fast-hole EDM drilling produces small, deep holes in hard metals, including starter holes for wire EDM, and we tune every parameter to the behaviour of Alloy Steel, which is high strength and hardenability for demanding parts.
CNC EDM Drilling Capability for Alloy Steel
- Ø0.2–3 mm holes
- Deep aspect ratios
- Hardened-metal drilling
- Angled hole capability
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.
How CNC EDM Drilling Alloy Steel Works
Material is removed from the Alloy Steel workpiece by controlled electrical discharges across a dielectric gap, with no mechanical contact. Flushing, on/off pulse timing and electrode/wire feed are set to balance speed against surface finish.
Every job begins from your CAD model or 2D drawing. Fixturing and tool paths are planned so the most critical dimensions are produced in the most rigid, repeatable setup. Critical dimensions are checked on the first part and monitored through the run.
Achievable Tolerances for CNC EDM Drilling Alloy Steel
| Feature | Standard | Precision |
|---|---|---|
| Profile dimension | ±0.010 mm | ±0.002 mm |
| Internal corner radius | 0.15 mm | 0.05 mm |
| Taper control over 50 mm | 0.02 mm | 0.005 mm |
| Surface finish (skim passes) | Ra 0.8 µm | Ra 0.2 µm |
| Recast layer | 10 µm | 2 µm (fine skim) |
| Start-hole diameter | 1.0 mm | 0.25 mm |
| Workpiece hardness | no limit (conductive) | no limit (conductive) |
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.
Secondary Operations & Finishing
We complete Alloy 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.
Design Tips for CNC EDM Drilling Alloy Steel
A few design choices make a real difference to cost and quality. EDM suits sharp internal corners, thin ribs and hardened Alloy Steel that cannot be milled; allowing a small corner radius where possible speeds the cut. If you send your model early, we will return practical DFM feedback before you commit to production.
Working with Alloy Steel
Alloy Steel offers a useful combination of properties: it is high strength and hardenability for demanding parts. Those characteristics shape how we approach EDM — from tool and parameter selection to work-holding and coolant.
If your application is sensitive to alloy condition, we agree the specification in writing and document it. Stock is sourced from reputable suppliers so what you order is what you receive.
CNC EDM Drilling Tolerances & Surface Finish
EDM holds tolerances to roughly ±0.002–0.005 mm with no cutting force on the Alloy Steel part, producing fine, controlled surface textures and sharp internal corners impossible to mill.
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 EDM Drilling Quality & Inspection
Consistent quality comes from disciplined process control. Critical dimensions on Alloy 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.
Applications of CNC EDM Drilling Alloy Steel
CNC EDM Drilling of Alloy 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 EDM Drilling Alloy Steel
Ordering Alloy 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.
Parts We Have Run in Alloy Steel
Three representative CNC EDM Drilling Alloy Steel jobs, with the callouts that actually drove the process plan. Yours will differ — these are here so you can judge whether your part is in our range before you spend time on an RFQ.
Micro slot in nozzle
- Material
- Alloy Steel
- Size
- 0.15 mm wide × 6 mm deep
- Key callouts
- Width ±0.003 mm
- Batch
- 400 pcs
Cut with 0.1 mm wire; the start hole is EDM-drilled at Ø0.3 mm.
Carbide punch
- Material
- Alloy Steel
- Size
- Ø6 × 45 mm
- Key callouts
- OD ±0.003 mm, sharp form retained
- Batch
- 250 pcs
Carbide is EDM or grind only; there is no milling route.
Injection mould cavity rib
- Material
- Alloy Steel
- Size
- 0.25 mm wide × 8 mm deep
- Key callouts
- Width ±0.005 mm, VDI 21 finish
- Batch
- 45 pcs
Sinker EDM with a graphite electrode; a cutter that thin would break in the first pass.
Finishing Options for 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 EDM Drilling 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 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.
Other Metals for CNC EDM Drilling
Other Processes for Alloy Steel
Send the drawing, the Alloy Steel grade and the quantity. You get pricing, lead time and any DFM notes back — usually within one business day.
Request a QuoteFrequently Asked Questions
Does CNC EDM Drilling Alloy Steel require dedicated tooling?
Wire EDM needs no shaped tooling; sinker EDM uses a shaped electrode we produce in-house for your cavity.
What material thickness or size range suits CNC EDM Drilling Alloy Steel?
We machine Alloy Steel across a broad size range; share your part envelope for confirmation.
What tolerances can you hold for CNC EDM Drilling Alloy Steel?
Achievable tolerances for Alloy Steel EDM machining depend on the alloy, geometry and feature size. EDM holds tolerances to around ±0.002 mm with no cutting force on the part. Exact figures are confirmed against your drawing callouts.
Why is Alloy Steel a good choice for CNC EDM Drilling?
Alloy Steel is high strength and hardenability for demanding parts, which makes it well suited to CNC EDM Drilling. We tune the process to the alloy so the finished Alloy Steel EDM machining part meets your dimensional and functional requirements.
Which industries use CNC EDM Drilling Alloy Steel parts?
CNC EDM Drilling Alloy Steel parts are used across aerospace, medical, automotive, electronics, semiconductor and general industrial sectors — anywhere precise Alloy Steel components are required.
What is CNC EDM Drilling Alloy Steel and how is it done?
CNC EDM Drilling Alloy Steel refers to fast-hole EDM drilling produces small, deep holes in hard metals, including starter holes for wire EDM. Applied to Alloy Steel — high strength and hardenability for demanding parts — VT machining produces each part to your CAD drawing, selecting parameters from your tolerance, finish and quantity requirements.