EN353

EN353 Alloy Steel Product Overview

EN353, also known as 815M17 or 20NiCrMo5 (DIN), is a low-alloy, nickel-chromium-molybdenum case-hardening steel under the BS 970 standard. Renowned for its high strength, excellent toughness, and good wear resistance, EN353 is designed for applications requiring a hard, wear-resistant surface and a tough core. Typically supplied in the annealed condition (max 229 HB), it achieves a surface hardness of 58–62 HRC after carburising, quenching, and tempering. The presence of nickel, chromium, and molybdenum ensures high tensile strength, good ductility, and impact resistance, even at low temperatures, making it ideal for heavy-duty automotive and engineering applications.

Applications

EN353 is primarily used in applications requiring high strength, durability, and wear resistance:

Automotive:

• Heavy-duty gears, pinions, and camshafts.
• Crankshafts, gudgeon pins, and drive shafts.
• Axles, clutch components, and transmission parts.

Engineering Components:

• Tool holders, jigs, and forging dies.
• High-load machine parts in mining and construction equipment.
• Precision components like spindles and couplings.

Other Uses:

• Aerospace components, such as high-strength fasteners and structural parts.
• Industrial machinery parts requiring high wear resistance and toughness.
• Components for oil and gas equipment, such as pump shafts.

Chemical Composition

The chemical composition of EN353 ensures its strength, toughness, and case-hardening properties:

• Nickel (Ni): Enhances toughness, fatigue resistance, and low-temperature impact strength.
• Chromium (Cr): Improves hardenability, wear resistance, and corrosion resistance.
• Molybdenum (Mo): Increases strength and resistance to tempering.
• Carbon (C): Low content ensures core ductility, with surface hardness achieved via carburising.

Supply Size

EN353 is available in various forms and sizes to meet industrial requirements:

• Round Bars:
  Diameter 16 mm to 700 mm.
• Flat Bars:
  Minimum: 10 mm thickness x 80 mm width.
  Maximum: 500 mm thickness x 2000 mm width.