EN Round Bar – A Comprehensive Guide for Engineers & Industries

IS 2062 is a product standard published by the Bureau of Indian Standards (BIS) for hot-rolled low, medium, and high tensile structural steel. This standard specifies the requirements for chemical composition, mechanical properties, testing methods, and dimensional tolerances of steel used in structural and general engineering applications.

IS 2062 is applicable to plates, sections, flats, bars, and other structural steel products. The standard is crucial for ensuring the quality and consistency of steel used in load-bearing and safety-critical applications.

1. EN8 Round Bar (Medium Carbon Steel)

• Carbon: 0.36–0.44%

• Manganese: 0.60–1.00%

• Strength: ~600–800 MPa after heat treatment

• Features: Good tensile strength, moderate wear resistance, excellent machinability.

• Applications: Shafts, studs, bolts, axles, keys, automotive components.

2. EN19 Round Bar (Chromium-Molybdenum Alloy Steel, AISI 4140 Equivalent)

• Carbon: 0.35–0.45%

• Chromium: 0.90–1.20%

• Molybdenum: 0.15–0.25%

• Strength: ~850–1000 MPa (quenched & tempered)

• Features: High tensile strength, good fatigue resistance, excellent toughness under dynamic load.

• Applications: Gears, spindles, high-performance shafts, bolts, coupling

3. EN24 Round Bar (Nickel-Chromium-Molybdenum Alloy Steel, AISI 4340 Equivalent)

• Carbon: 0.36–0.44%

• Nickel: 1.30–1.80%

• Chromium: 0.90–1.40%

• Molybdenum: 0.25–0.35%

• Strength: ~850–1000 MPa after hardening and tempering

• Features: Exceptional toughness, high wear resistance, impact strength, and shock resistance.

• Applications: Heavy-duty shafts, aircraft components, transmission gears, aerospace and automotive application

Mechanical Properties of EN Round Bars

Tensile Strength: 500–1000 MPa (depending on grade & heat treatment)

Yield Strength: 250–850 MPa

Hardness (Brinell): 180–320 HB (varies by grade)

Elongation: 10–25%

Impact Resistance: Excellent, especially in alloy grades like EN19 & EN24.

Heat Treatment Options

One of the major advantages of EN round bars is their ability to undergo heat treatment, which tailors their properties to suit specific applications.

• Annealing – Improves machinability and relieves stress.

• Quenching & Tempering – Enhances hardness and strength.

• Carburizing – For surface hardness while maintaining a ductile core.

Applications of EN Round Bars

1. Automotive Industry

• Crankshafts, camshafts, connecting rods, transmission shafts, and suspension parts rely on EN round bars for durability and strength.

2. Aerospace & Defense

• EN24 is widely used in aircraft landing gears, engine components, and helicopter shafts due to its toughness and shock resistance.

3. General Engineering

• Manufacturing of gear wheels, pinions, heavy-duty spindles, and tool holders.

4. Oil & Gas / Marine Industry

• Used in drill collars, couplings, heavy-duty fasteners, and high-strength shafts that must withstand corrosion and fatigue.

5. Construction & Heavy Equipment

• Foundation bolts, lifting equipment parts, and structural supports.

Advantages of EN Round Bars

1. High Strength-to-Weight Ratio – Provides reliable performance under load without unnecessary bulk.

2. Excellent Machinability – Allows for precision components with minimal tool wear.

3. Good Fatigue Resistance – Suitable for rotating and reciprocating parts.

4. Heat Treatable – Offers flexibility for customized mechanical properties.

5. Cost-Effective – Provides high performance at a competitive cost compared to exotic alloys.