AFNOR 35NCD14 Alloy Steel Bar 35NCD14 Round Bars 35NCD14 Rod

Product Description

The AFNOR 35NCD14 is a high-performance, high-hardenability nickel-chromium-molybdenum alloy steel specified under the French AFNOR standard. It is renowned for its exceptional tensile strength, toughness, and fatigue resistance, making it a staple material in aerospace, defense, and heavy-duty mechanical engineering applications.

Here is a comprehensive breakdown of its technical specifications, equivalents, chemical composition, and typical applications for round bars and rods.

🛠️ Chemical Composition (%)

The precise balance of nickel ($Ni$), chromium ($Cr$), and molybdenum ($Mb$) gives this grade its deep-hardening characteristics and excellent impact toughness.

🔄 International Equivalents

While 35NCD14 is uniquely heavily alloyed (especially with its high nickel content near 4%), it closely aligns with or replaces several global high-tensile standards:

• Germany (DIN / WNr): 36CrNiMo16 / 1.6773

• United Kingdom (BS): 835M30

• USA (AISI/SAE): Closest to 4340 / E4340 (Note: 35NCD14 has significantly higher Nickel content for superior toughness at high strength levels)

• Europe (EN): 36NiCrMo16

• Italy (UNI): 38NiCrMo16

📈 Mechanical Properties (Typical Heat-Treated State)

When quenched and tempered, 35NCD14 round bars achieve a remarkable combination of high tensile strength and high yield stress without becoming brittle.

• Tensile Strength ($R_m$): $1100 - 1300\text{ MPa}$ (can exceed $1500\text{ MPa}$ depending on heat treatment)

• Yield Strength ($R_{e}$): $\ge 900\text{ MPa}$

• Elongation ($A_5$): $\ge 10\%$

• Impact Energy ($KV$): $\ge 35\text{ J}$ (at room temperature)

⚙️ Key Technical Features

• Deep Hardenability: Thanks to the high nickel and chromium content, heavy-section round bars maintain uniform mechanical properties from the surface right to the core.

• Fatigue & Impact Resistance: Excellent performance under cyclic loading and high-stress shock environments.

• Machinability: Best machined in the annealed or normalized condition; requires rigid setups and carbide tooling if machined in the fully hardened state.

🚀 Typical Applications

Because of its premium structural integrity, 35NCD14 round bars and rods are heavily utilized in critical components:

• Aerospace & Defense: Landing gear components, high-stress structural shafts, and engine mountings.

• Automotive & Motorsport: High-torque drive shafts, crankshafts, connecting rods, and stub axles.

• Heavy Machinery: Heavy-duty gears, pinions, turbine rotors, and high-tensile clamping bolts/fasteners.

Available Supply Forms

• Finishes: Hot-rolled, forged, cold-drawn, centerless ground, or turned.

• Heat Treatment States: Supplied as annealed (for ease of machining) or pre-hardened (Quenched + Tempered to specific strength bands).