VT machining offers CNC Milling for EN24 Steel (BS 970 817M40 / ~4340 / 34CrNiMo6), typically supplied Q&T (T condition). British designation broadly equivalent to 4340; tougher than EN19.
CNC Milling Notes for EN24 Steel
EN24 Steel mills well with conventional strategies; finishing passes are planned to meet flatness and finish callouts.
For estimating, a 100 × 100 × 10 mm block of EN24 Steel weighs about 0.79 kg.
Starting Parameters for CNC Milling EN24 Steel
| Cutting speed (carbide) | 105-185 m/min |
|---|---|
| Feed per tooth | 0.035-0.123 mm |
| Spindle speed, Ø10 mm end mill | 3340-5890 rpm |
| Insert / tool class | ISO P — CVD-coated carbide |
| Coolant | Emulsion (5-8%); dry is possible for interrupted cuts |
| Thermal growth, 100 mm part, +10 °C | 11.7 µm (CTE 11.7 µm/m·K) |
Starting values for EN24 Steel, Q&T (T condition); optimised on the first article.
EN24 Steel Data Relevant to CNC Milling
| Equivalent designations | BS 970 817M40 / ~4340 / 34CrNiMo6 |
|---|---|
| Key composition | C 0.36-0.44%, Ni 1.3-1.7%, Cr 1-1.4%, Mo |
| Typical supply condition | Q&T (T condition) |
| Hardness (typical) | ~28-34 HRC |
| Machinability rating | 55% (AISI B1112 = 100%) |
Typical values; we work to your drawing and mill certificate.
How EN24 Steel Differs
British designation broadly equivalent to 4340; tougher than EN19.
Typical applications: Heavy-duty shafts, gears, connecting rods.
EN24 Steel vs Similar Grades
| EN24 Steel | EN19 Steel | 20CrMnTi Steel | 42CrMo Steel | |
|---|---|---|---|---|
| Key composition | C 0.36-0.44%, Ni 1.3-1.7%, Cr 1-1.4%, Mo | C 0.36-0.44%, Cr 0.9-1.2%, Mo 0.25-0.35% | C 0.17-0.23%, Cr 1-1.3%, Mn 0.8-1.1%, Ti | C 0.38-0.45%, Cr 0.9-1.2%, Mo 0.15-0.25% |
| Hardness | ~28-34 HRC | ~28-32 HRC | ~58-62 HRC case | ~28-32 HRC |
| Tensile (MPa) | ~850-1000 | ~850-1000 | ~1080 core | ~1080 Q&T |
| Machinability % | 55 | 62 | 60 | 62 |
| Typical use | Heavy-duty shafts, gears, connecting rods | Shafts, gears, studs | Automotive gears, shafts | Gears, shafts, high-strength bolts |
More on CNC Milling Steel
Finishing options, quality documentation and general cnc milling guidance for all steel grades are on our CNC Milling Steel page.
No drawing yet? Sketch the part in our free 3D + 2D builder and send it with your RFQ.
Quoting CNC Milling EN24 Steel
Send a STEP/IGES model or PDF drawing, confirm EN24 Steel and its condition (we usually see it supplied Q&T (T condition)), the quantity, critical tolerances and any finish or certificate requirements.
EN24 Steel in Other Processes
Related
Send the drawing, the EN24 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 EN24 Steel with CNC Milling?
Surface finish on EN24 Steel is controlled to your specification; we confirm the achievable Ra against your callout.
Which industries use CNC Milling EN24 Steel parts?
CNC Milling EN24 Steel parts are used across aerospace, medical, automotive, electronics, semiconductor and general industrial sectors — anywhere precise EN24 Steel components are required.
Can VT machining make custom EN24 Steel parts to my drawing?
Yes. EN24 Steel machining is made to order from your CAD/2D drawing. Share your geometry, material grade, tolerance and quantity and we will confirm feasibility, lead time and pricing.
Does CNC Milling EN24 Steel require dedicated tooling?
Most EN24 Steel machining work uses standard cutting tools and CNC programs; dedicated fixtures are made only when geometry or volume requires them.