Steel EN353
BS 970 815M17, EN353 / 665M17
EN353 is a low-carbon nickel-chromium-molybdenum case-hardening (carburizing) steel, equivalent in intent to BS 970 815M17 and close to 20CrNi2Mo/20NiCrMo grades, widely used in India and Asia for gears, pinions, shafts, camshafts and splined parts.
Values for the HR condition
EN353 tempers and conditions
EN353 is supplied in 7 conditions, soft to hard. HR is the default FabDigit quotes; the values on this page are for it.
Compare all 7 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
full/spheroidize annealed for machining and cold work | Pick for deep machining, broaching, hobbing or cold forming before carburizing. | 400 | 620 | 22 | 190 HB | — |
HRDefault Hot rolled | Standard stocked condition for gear blanks and forging stock; machined then carburized. | 480 | 760 | 18 | 20 HRC | 7.8 % IACS |
880–920 °C air cooled | Use to refine grain and homogenize forgings before carburizing; uniform machining response. | 550 | 800 | 16 | 22 HRC | 7.8 % IACS |
Cold rolled | For flat product and stamped/carburized components needing good surface and thickness tolerance. | 600 | 780 | 14 | 23 HRC | 7.8 % IACS |
Cold drawn | Choose for close size tolerance, bright finish and higher as-supplied strength on small-diameter bar. | 660 | 830 | 12 | 24 HRC | 7.8 % IACS |
Quenched and tempered | Direct hardening without carburizing when a tough, uniformly strong shaft or fastener core is wanted. | 800 | 1,000 | 13 | 32 HRC | — |
Carburized and hardened | The service condition for gears and pinions — hard wear-resistant case on a tough 30–42 HRC core. | 900 | 1,150 | 10 | 60 HRC | — |
What is EN353?
EN353 is a low-carbon nickel-chromium-molybdenum case-hardening (carburizing) steel, equivalent in intent to BS 970 815M17 and close to 20CrNi2Mo/20NiCrMo grades, widely used in India and Asia for gears, pinions, shafts, camshafts and splined parts. It is chosen for a very hard, wear- and pitting-resistant carburized case (58–62 HRC) over a tough, high-strength core (typically 30–42 HRC) with good hardenability in medium sections. Limits are its low corrosion resistance, restricted weldability after carburizing, and the need for controlled heat treatment plus grinding allowance because of distortion and retained austenite in the case. EN353 has a density of 7.85 g/cm³ (0.284 lb/in³), heavier than 56% of steel grades. It melts at 1,420°C (2,588 °F). EN353 has a yield strength of 480 MPa (69.6 ksi) and a tensile strength of 760 MPa (110 ksi) — stronger than 59% of steel grades. Elongation at break is 18% and the elastic modulus is 210 GPa (30.5 Msi).
What is EN353 used for?
- Gears
- Industrial drive shafts
- Pins
Limitations
- Limited service temperature — 200°C (392 °F), worse than 93% of steel grades
EN353 properties
Typical room-temperature values for EN353-HR; bars are the position among steel grades.
Physical3
EN353 has a density of 7.85 g/cm³ (0.284 lb/in³), heavier than 56% of steel grades. It melts at 1,420°C (2,588 °F).
Mechanical17
EN353 has a yield strength of 480 MPa (69.6 ksi) and a tensile strength of 760 MPa (110 ksi) — stronger than 59% of steel grades. Elongation at break is 18% and the elastic modulus is 210 GPa (30.5 Msi).
Thermal6
EN353 is rated for continuous service to 200°C (392 °F). It conducts heat at 44 W/m·K (25.4 BTU/hr·ft·°F), better than 57% of steel grades. Thermal expansion is 11.8 µm/m·K (6.56 µin/in·°F).
Electrical3
EN353 conducts electricity at 7.8 % IACS, worse than 57% of steel grades.
Chemical & Environmental3
Corrosion resistance is not recommended (12/100), worse than 53% of steel grades.
Sustainability4
Producing a kilogram of EN353 takes about 30 MJ of energy and emits 2.1 kg of CO₂ — more than 56% of steel grades. Typical recycled content is 25%.
Manufacturability7
EN353's machinability is good (55/100, better than 62% of steel grades); weldability fair (42/100); formability fair (45/100).
Common Calculations5
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
Strength versus weight in the steel family
Yield strength against density for every steel grade FabDigit runs. EN353 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with EN353
Is EN353 easy to machine?
Machine fully in the annealed or normalized state with carbide tooling (~120–180 m/min); after carburizing only grinding, honing or CBN hard-turning is practical.
Can EN353 be welded?
Weldable only before carburizing — preheat 200–250 °C, low-hydrogen consumables, post-weld stress relief; welding a carburized case will crack it.
Can EN353 be formed, bent or molded?
Hot forge at 1100–1150 °C and normalize afterwards; cold forming is limited to gentle bends in the annealed condition.
Manufacturability
The process limits FabDigit applies to EN353. Every EN353 part is priced by an engineer; design inside these and the quote comes back without a redesign loop.
CNC machining
| Machinability | Better55 / 100 |
|---|---|
| ISO material group | P.2 |
| Cutting speed (rough / finish) | 180 / 210 m/min |
| Minimum wall | 0.8 mm |
| Minimum internal radius | 1 mm |
| Drill depth limit | 5× diameter |
| Best surface (machined / polished) | Ra 1.6 / — |
| Hardenable after machining | No |
Sheet metal
| Formability | Better45 / 100 |
|---|---|
| Weldability | Better42 / 100 |
EN353 chemical composition (wt %)
Limits by weight percent from the governing specification, written the way the spec states them — a single maximum for impurities, a range for alloying elements, and the base element as balance. Nominal is the typical mid-range value.
| Element | Spec limit (wt %) | Nominal |
|---|---|---|
| Ccase-hardening carbon level | 0.14 – 0.2 | 0.17 |
| Si | 0.15 – 0.35 | 0.25 |
| Mn | 0.6 – 0.9 | 0.75 |
| P | ≤ 0.04 | |
| S | ≤ 0.04 | |
| Cr | 0.75 – 1.25 | 1 |
| Ni | 1 – 1.5 | 1.25 |
| Mo | 0.08 – 0.15 | 0.12 |
| Fe | balance |
What surface finishes work on EN353?
No natural corrosion resistance — protect with oil, phosphate, black oxide, zinc/manganese phosphate or plating; keep 0.1–0.3 mm grinding stock for post-carburizing distortion.
Surface treatments FabDigit runs on steel parts — pick them in the quote configurator or call them out on the drawing. Each links to its datasheet in the surface-finish library (thickness, specs, call-out, material verdicts).
Plating
CVD Coating
Black / Phosphate
Thermal Spray
Equivalent designations
Standards and trade names that resolve to Steel EN353 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
How much does EN353 cost?
EN353 is a standard-cost steel ($$), cheaper than about 71% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
EN353 — frequently asked
What is EN353 used for?
EN353 is typically used for gears, industrial drive shafts and pins. In short: premium carburizing alloy bar.
What is the yield strength of EN353?
EN353 has a typical yield strength of 480 MPa (69.6 ksi) and a tensile strength of 760 MPa (110 ksi) — stronger than 59% of steel grades. Strength varies by condition: see the 7 listed tempers.
Is EN353 easy to machine?
Reasonably — machinability is rated good (55/100, better than 62% of steel grades). Machine fully in the annealed or normalized state with carbide tooling (~120–180 m/min); after carburizing only grinding, honing or CBN hard-turning is practical.
Can EN353 be welded?
With care — weldability is rated fair (42/100). Weldable only before carburizing — preheat 200–250 °C, low-hydrogen consumables, post-weld stress relief; welding a carburized case will crack it.
What surface finishes work on EN353?
No natural corrosion resistance — protect with oil, phosphate, black oxide, zinc/manganese phosphate or plating; keep 0.1–0.3 mm grinding stock for post-carburizing distortion.
Can EN353 be formed, bent or molded?
Hot forge at 1100–1150 °C and normalize afterwards; cold forming is limited to gentle bends in the annealed condition.
What is the maximum service temperature of EN353?
EN353 is rated for continuous use to about 200°C (392 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between EN353-HR and EN353-CH?
HR is the default condition — standard stocked condition for gear blanks and forging stock; machined then carburized. CH: the service condition for gears and pinions — hard wear-resistant case on a tough 30–42 HRC core. Yield strength is 480 MPa in HR versus 900 MPa in CH.
How much does EN353 cost?
EN353 is a standard-cost steel ($$), cheaper than about 71% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
Can FabDigit make parts in EN353?
Yes — EN353 is available for CNC machining and sheet metal; every part is priced by an engineer rather than instantly. Upload a STEP file to get a price and a DFM check.
Sources
- BS 970-3: Wrought steels — 815M17 case hardening steel — BSI (1991)
- GB/T 3077 (20CrNi2Mo) — SAC (2015)
- ASM Handbook Vol.1 — Properties and Selection: Irons, Steels — ASM International (1990)
- ASM Handbook Vol.4 — Heat Treating (Carburizing) — ASM International (1991)
- Alloy carburizing bar steel datasheets (EN353 / 815M17 / 20CrNi2Mo) — Various bar producers (2023)
- SMM / Mysteel — SMM / Mysteel (2026)
Property data is compiled from published supplier and standards handbooks and normalised for comparison; hardness values on non-Brinell scales are converted approximately for charting only. Manufacturability limits are FabDigit quote-engine defaults and may be relaxed by engineering review. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.