EN 24 round bar — ready stock in Mumbai
We supply EN 24 (817M40 / 4340) as round bar, Ø16–205 mm, from ready stock at Darukhana, Mumbai. Cutting is available if the balance piece is also taken, and every dispatch ships with a mill test certificate.
Need the weight? Use our round bar weight calculator — kg per metre and total weight for any size.
Related guides: EN24 vs EN24T · EN24 vs EN19 vs EN8 · Hardness in HRC · Equivalent grades chart
Datasheet: Download the EN 24 / 817M40 datasheet (PDF, 2 pages)
EN 24 (817M40 / 34CrNiMo6) is a high-tensile through-hardening nickel-chromium-molybdenum alloy steel. We stock it annealed (Ø16–100 mm) and as-rolled (Ø105–205 mm); hardened and tempered EN24T is supplied against orders of 3–5 tons. It combines very high strength with excellent toughness, ductility and fatigue resistance, and its high hardenability lets it develop uniform properties even in large sections. It is a standard choice for heavily loaded, safety-critical components.
Weight %, balance iron. Left: what we actually supply. Right: the international standard, for reference. The mill range is slightly wider than 817M40 for carbon, chromium, nickel, phosphorus and sulphur; the recent heat we checked sits inside the BS 970 limits. If your drawing calls for the strict standard, mention it in your enquiry. Every dispatch comes with the mill test certificate for its heat.
| Element | As supplied: Indian mill range, % | Standard: 817M40, BS 970, % |
|---|---|---|
| Carbon (C) | 0.35–0.45 | 0.36–0.44 |
| Silicon (Si) | 0.10–0.35 | 0.10–0.35 |
| Manganese (Mn) | 0.45–0.70 | 0.45–0.70 |
| Phosphorus (P) | max 0.050 | max 0.035 |
| Sulphur (S) | max 0.050 | max 0.040 |
| Chromium (Cr) | 0.90–1.40 | 1.00–1.40 |
| Nickel (Ni) | 1.30–1.80 | 1.30–1.70 |
| Molybdenum (Mo) | 0.20–0.35 | 0.20–0.35 |
Hardened-and-tempered property levels by ruling section (EN 10083-3).
| Dimension (+QT) | Yield Rp0.2 (MPa) | Tensile Rm (MPa) | Elong. A5 (%) | Red. of area Z (%) | Hardness | Impact Kv |
|---|---|---|---|---|---|---|
| Ø up to 16 mm | 1000 min | 1200–1400 | 9 min | 40 min | 359–404 HB | — |
| Ø 16–40 mm | 900 min | 1100–1300 | 10 min | 45 min | 331–380 HB | 45 J |
| Ø 40–100 mm | 800 min | 1000–1200 | 11 min | 50 min | 298–359 HB | 45 J |
| Ø 100–160 mm | 700 min | 900–1100 | 12 min | 55 min | 271–331 HB | 45 J |
| Ø 160–250 mm | 600 min | 800–950 | 13 min | 55 min | 240–286 HB | 45 J |
| Soft annealed (+A) | — | — | — | — | max. 248 HB | — |
| Transformation point | Temperature (°C) |
|---|---|
| Ac1 | 715 |
| Ac3 | 770 |
| Ms | 320 |
| Mf | 100 |
| Treatment | Temperature cycle | Cooling / quenching |
|---|---|---|
| Hot forging | 900–1100 °C | In still air |
| Normalizing | 860–880 °C | In still air |
| Soft annealing | 650–680 °C | Furnace cool (HB max. 248) |
| Hardening | 830–860 °C | Quench in oil |
| Tempering | 540–660 °C | In air |
| Stress relieving | 550–650 °C | In still air |
Indicative curves from published band data (EN 10083-3), for a reference oil quench of 850 °C. EN 24 is a deep-hardening grade, so the Jominy band stays high across the bar.
Typical values at ambient temperature unless stated.
| Property | Typical value |
|---|---|
| Young’s modulus | 205 GPa |
| Poisson’s ratio | 0.30 |
| Shear modulus | 80 GPa |
| Density | 7,850 kg/m³ |
| Thermal expansion (20–300 °C) | 12.5 µm/m·K |
| Specific heat | 460 J/kg·K |
| Thermal conductivity | 38 W/m·K |
| Electrical resistivity | 0.19 µΩ·m |
What sizes of EN 24 do you stock?
EN 24 round bar from Ø16 to Ø205 mm, from ready stock at Darukhana, Mumbai. We do not stock EN 24 in square or flat.
What is the minimum order quantity?
Our minimum order is 100 kg.
Do you cut bars to size?
Yes. Cutting is available provided the balance piece is also taken by the buyer; cutting is charged extra.
Is delivery included in the price?
Prices are ex-Darukhana, Mumbai. Loading, transport and cartage are extra, charged at actuals.
Do you provide a mill test certificate?
Yes. Every dispatch is accompanied by a mill test certificate stating the actual results for that heat.
What are the equivalent grades of EN 24?
Common equivalent designations for EN 24 include 817M40, 34CrNiMo6, 1.6582, AISI 4340, SNCM439, 35NiCrMo6. Please confirm suitability for your application with our team.
Need EN 24 in a specific size?
We hold EN 24 round bar in ready stock from Ø16mm to Ø205mm. Send us the size and quantity for a fast quote.
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