EN353 Forgings
EN353 is the heavy-duty case hardening grade — nickel and chromium give it both a deeper achievable case and a stronger core than 20MnCr5, which matters when gear loads rise and module sizes grow.
- Carbon
- 0.17 – 0.23%
- Nickel
- 1.00 – 1.50%
- Chromium
- 0.75 – 1.25%
- Case Hardness
- 58 – 62 HRC
- Core Hardness
- 35 – 45 HRC
- Equivalent
- AISI 8620 family, EN353
EN353 Forgings at a glance
Quotable facts from Avadh Techno Forge, Gundasara, Gondal, Rajkot.
- Carbon: 0.17 – 0.23%
- Nickel: 1.00 – 1.50%
- Chromium: 0.75 – 1.25%
- Case Hardness: 58 – 62 HRC
- Core Hardness: 35 – 45 HRC
- Equivalent: AISI 8620 family, EN353
Deeper Case, Stronger Core
Where 20MnCr5 tops out, EN353 carries case depths beyond 1.5 mm with a core strength that supports large-module gear teeth under high torque. That is the difference between a tooth that pits and one that survives the design life.
- Case depth beyond 1.5 mm achievable
- Higher core strength than 20MnCr5
- Good dimensional stability
- Suits large module gears
Distortion Behaviour
Alloying improves hardenability, allowing gentler quenching, which reduces distortion during carburising — a serious practical advantage on large gears where post-hardening grinding stock is limited.
Applications
Heavy-duty transmission gears, bevel and hypoid pinions, differential components, industrial gearbox parts and high-torque splined shafts.
EN353 Chemical Composition and Case Properties
EN353 is a nickel-chromium case hardening steel used where gear modules grow and torque rises beyond what 20MnCr5 comfortably handles. The nickel addition raises core strength and supports deeper achievable case depths, while improving hardenability enough that gentler quenching — and therefore less distortion — becomes possible on large gears.
| Property | Typical value |
|---|---|
| Carbon | 0.17 – 0.23% |
| Manganese | 0.60 – 0.90% |
| Nickel | 1.00 – 1.50% |
| Chromium | 0.75 – 1.25% |
| Molybdenum | ≈ 0.08 – 0.15% |
| Case hardness after carburising | 58 – 62 HRC |
| Core hardness | ≈ 35 – 45 HRC |
| Achievable case depth | Beyond 1.5 mm where specified |
EN353 in Large Gear Production
The practical advantage on big gears is distortion. Higher hardenability means the gear can be quenched less aggressively and still reach its required core properties, so it moves less during hardening — which matters when grinding stock on a large gear is limited and scrap is expensive. Typical applications are heavy-duty transmission gears, bevel and hypoid pinions, differential components and industrial gearbox parts. For very heavily loaded industrial and wind gearboxes, 18CrNiMo7-6 is the usual step up.
People also ask
When should I choose EN353 over 20MnCr5?
For large module gears, deep case requirements and high torque, where EN353's higher core strength supports bigger tooth loads.
Does EN353 distort less during carburising?
Its higher hardenability permits gentler quenching, which generally reduces distortion on large gears where grinding stock is limited.
Topics covered on this page
- EN353 forging manufacturer India
- case carburising steel forging
- heavy duty gear steel forging
- EN353 forged blanks supplier
Based on work carried out at our own forging plant at Gundasara, Gondal, Rajkot — operating since 2008.
Questions Answered
EN353 or 20MnCr5?
+
EN353 for large modules, deep case requirements and high torque; 20MnCr5 for standard automotive and general transmission gears at lower cost.
Does EN353 distort less during hardening?
+
Its higher hardenability permits gentler quenching, which generally reduces distortion on large parts.
What core hardness results?
+
Typically 35–45 HRC, higher than 20MnCr5, supporting bigger tooth loads.
Do you supply EN353 gear blanks?
+
Yes, forged near-net and proof machined to your hobbing allowance.