Ventura Alloy And Steels Private Limited

EN31 Round Bars – Material Description

EN31 is a high-carbon chromium alloy steel known for its high hardness, excellent wear resistance, and high fatigue strength. It retains dimensional stability after heat treatment and is widely used for high-precision, wear-resistant components such as bearings and shafts.

Equivalent to AISI 52100 / SAE 52100 / 100Cr6, EN31 is typically supplied in round bar form for machining into critical parts requiring superior surface hardness and durability.

Chemical Composition (Typical %) Available Sizes of Round Bars

Hot Rolled (Annealed) Round Bars

• Sizes: 16 mm to 200 mm dia

• Condition: Annealed (for machining and further hardening)

Peeled / Turned / Ground Round Bars

• Sizes: 12 mm to 120 mm dia

• Condition: Peeled, straightened, and tight tolerance

• Surface Finish: Bright (suitable for precision components)

Forged Round Bars

• Sizes: 150 mm and above

• Application: Custom sizes for shafts and heavy machinery parts

Mechanical Properties (After Heat Treatment) Heat Treatment Response

Annealed Condition:

• Soft for machining (approx. 200 HB)

Hardened & Tempered Condition:

• Quenching at 840–860°C in oil or polymer

• Tempering at 150–200°C to achieve 60–65 HRC

Stress Relieving:

• Done after rough machining and before final hardening

Typical Applications

Bearings:

• Ball & roller bearings, bearing races, needle bearings

Automotive:

• Gear pins, transmission shafts, CV joints, engine parts

Tooling & Dies:

• Punches, spindles, wear-resistant tools

Machinery & Hydraulics:

• Piston rods, guide pins, heavy-duty shafts

Product Condition & Supply Form Key Advantages

✅ Excellent hardness and wear resistance
✅ High fatigue and impact strength
✅ Good machinability in annealed condition
✅ Trusted, industry-standard grade for bearing and automotive applications

EN24 steel (also designated SAE 4340, AISI 4340, or 34CrNiMo6 in European standards) is a medium carbon, low-alloy high-strength steel containing nickel, chromium, and molybdenum. This alloying mix gives the steel a strong balance of high tensile strength, toughness, fatigue resistance, and hardenability — making it suitable for demanding mechanical applications.

Typical Chemical Composition (approx.):

• Carbon (C): ~0.36–0.44%

• Manganese (Mn): ~0.45–0.80%

• Chromium (Cr): ~0.7–1.4%

• Nickel (Ni): ~1.3–2.0%

• Molybdenum (Mo): ~0.20–0.40%

Mechanical Characteristics:

• High tensile strength (can be 850–1080 MPa or higher in heat-treated condition)

• Good toughness and impact resistance

• Excellent hardenability for deep section heat treatment

• Wear resistance and fatigue strength

• Moderate weldability (best with pre- and post-heat treatment)

Forms & Finishes:
EN24 / SAE 4340 round bars are supplied in various surface finishes — hot rolled, bright, peeled, turned, or polished — in diameters typically from small rods up to large engineering bars depending on the mill and customer requirements.

Heat Treatment:

• Supplied in annealed, as-rolled, or quenched & tempered conditions

• Quenching and tempering typically optimize strength and toughness

• Can be surface hardened (induction, nitriding) for wear-resistant parts

🔧 Key Applications of EN24 / SAE 4340 Round Bars

EN24 / SAE 4340 is used wherever high strength, shock resistance, and reliability under stress are required. Typical industries and components include:

🚗 Automotive & Transportation

• Crankshafts and camshafts

• Gears and pinions

• Axles and drive shafts

✈️ Aerospace & Defense

• Landing gear and critical aircraft structural parts

• Rotor hubs and engine components

🛠 Industrial Machinery

• Heavy-duty shafts

• Couplings, spindles, and pins

• Studs, bolts, and fasteners

🛢 Oil & Gas / Offshore

• Drill shafts and downhole tools

• High stress pressure parts

🏗 Heavy Equipment & Construction

• Load-bearing shafts and structural parts in cranes, rolling mills, mining gear, and material-handling machines

⚙️ General Engineering

• Precision machined components

• Tooling components requiring strength + toughness

Why Choose EN24 / SAE 4340 Round Bars

✔ Superior strength and fatigue resistance compared to many carbon steels
✔ Good machinability in annealed condition
✔ Excellent performance after heat treatment
✔ Versatile in heavy-duty and high-stress applications

A case hardening steel with a carbon content between 0.14 and 0.19% Is used for surface hardening when grouting, nitrocarburising, nitriding and for other typesof surface chemical - treatment. It has application in manufacturing Shafts, Axles, Gears, Gear Wheels, bolts, levers among others.