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Steel C25 +N (Normalized)

Heat-treated state · default condition

EN C25

Standard stocked condition — uniform fine grain, balanced strength/toughness for shafts, pins and forgings.

Budget cost $

Values for the +N condition

Other C25 tempers and conditions

C25 is listed in 6 conditions; see the grade overview at C25.

Compare all 6 conditionsHide
Condition · open for datasheetBest forYield MPaTensile MPaElong. %HardnessConductivity
Annealed
Choose for maximum ductility before heavy cold forming, deep drawing or cold heading.22040032111 HB—
Hot rolled
Cheapest mill condition for weldments and non-critical structural parts; scale and looser tolerances.22540025116 HB—
+NDefaultThis page
Normalized
Standard stocked condition — uniform fine grain, balanced strength/toughness for shafts, pins and forgings.26544030126 HB—
Induction hardened
Selected when only local wear resistance is needed on shaft journals; maximum attainable case hardness is limited by the 0.25 % C content.2654402442 HRC9.5 % IACS
Cold drawn
Pick for close tolerance, bright surface and higher yield strength on automatic-lathe parts; lower ductility and residual stress.39047015137 HB—
Quenched and tempered
Use for small-section pins and bolts needing higher yield; hardenability is low so benefit disappears above ~25 mm diameter.4106102212 HRC—

What is C25 +N?

C25 +N is C25 heat treated to +N — standard stocked condition — uniform fine grain, balanced strength/toughness for shafts, pins and forgings. C25 +N has a yield strength of 265 MPa (38.4 ksi) and a tensile strength of 440 MPa (63.8 ksi) — weaker than 92% of steel grades. Elongation at break is 30% and the elastic modulus is 210 GPa (30.5 Msi). C25 +N has a density of 7.85 g/cm³ (0.284 lb/in³), heavier than 56% of steel grades. It melts at 1,425°C (2,597 °F).

Advantages

  • Ductile — tolerates forming and impact — 30%, better than 93% of steel grades
  • Conducts heat well — 51 W/m·K (29.5 BTU/hr·ft·°F), better than 92% of steel grades
  • Easy to machine — 62/100, better than 89% of steel grades
  • Readily welded — 88/100, better than 87% of steel grades
  • High electrical conductivity — 10 % IACS, better than 83% of steel grades

Limitations

  • Low strength — 265 MPa (38.4 ksi), worse than 92% of steel grades

C25 +N properties

Typical room-temperature values for C25 +N; 15 are specific to this condition. Other listed values are C25 reference data and may not represent this condition. Bars are the position among steel grades.

Physical3

C25 +N has a density of 7.85 g/cm³ (0.284 lb/in³), heavier than 56% of steel grades. It melts at 1,425°C (2,597 °F).

Density7.85 g/cm³0.28 lb/in³
Melting Point (Solidus)1,425°C2,597 °F
Liquidus Temperature1,515°C2,759 °F

Mechanical16

C25 +N has a yield strength of 265 MPa (38.4 ksi) and a tensile strength of 440 MPa (63.8 ksi) — weaker than 92% of steel grades. Elongation at break is 30% and the elastic modulus is 210 GPa (30.5 Msi).

Elastic (Young's) Modulus210 GPa30.5 Msi
Shear Modulus80 GPa11.6 Msi
Bulk Modulus160 GPa23.2 Msi
Poisson's Ratio0.29
Tensile Strength (Ultimate)440 MPa63.8 ksi
Yield Strength (0.2% offset)265 MPa38.4 ksi
Elongation at Break30%
Reduction in Area60%
Compressive Strength265 MPa38.4 ksi
Shear Strength265 MPa38.4 ksi
Fatigue Strength (Endurance Limit)215 MPa31.2 ksi
Fracture Toughness (K_IC)80 MPa·√m72.8 ksi·√in
Charpy V-Notch Impact (RT)65 J47.9 ft·lbf
Hardness, Brinell126 HB
Hardness, Rockwell B71 HRB
Hardness, Vickers132 HV

Thermal6

C25 +N is rated for continuous service to 400°C (752 °F). It conducts heat at 51 W/m·K (29.5 BTU/hr·ft·°F), better than 92% of steel grades. Thermal expansion is 11.9 µm/m·K (6.61 µin/in·°F).

Thermal Conductivity51 W/m·K29.5 BTU/hr·ft·°F
Specific Heat Capacity480 J/kg·K0.11 BTU/lb·°F
Thermal Expansion (CTE, 20–100 °C)11.9 µm/m·K6.6 µin/in·°F
Latent Heat of Fusion250 J/g107 BTU/lb
Max Service Temperature (continuous)400°C752 °F
Min Service Temperature-20°C-4 °F

Electrical3

C25 +N conducts electricity at 10 % IACS, better than 83% of steel grades.

Electrical Conductivity10 % IACS
Electrical Resistivity1.7×10⁻⁷ Ω·m6.69 µΩ·in
Magnetic Responseferromagnetic

Chemical & Environmental3

Corrosion resistance is not recommended (10/100), worse than 86% of steel grades.

Galvanic Potential (seawater, vs SCE)-0.61 V
Corrosion ResistanceNot recommended10/100
Chemical Resistance SummaryRusts freely in humid air, water and salt spray; attacked by acids and chlorides. Acceptable in dry oils, greases and alkaline media (pH > 10). Requires paint, zinc plating, phosphate/oiling or blackening for service.

Sustainability4

Producing a kilogram of C25 +N takes about 25 MJ of energy and emits 2 kg of CO₂ — less than 82% of steel grades. Typical recycled content is 28%.

Embodied Energy (primary production)25 MJ/kg10,748 BTU/lb
Embodied Carbon (primary production)2 kg CO₂/kg
Embodied Water40 L/kg4.8 gal/lb
Typical Recycled Content28%

Manufacturability8

C25 +N's machinability is good (62/100, better than 89% of steel grades); weldability excellent (88/100); formability good (65/100).

MachinabilityGood62/100
Machinability Rating (AISI 1212 = 100 %)65%
WeldabilityExcellent88/100
Formability (cold)Good65/100
CastabilityPoor30/100
Brazeability / SolderabilityVery good75/100
PolishabilityGood55/100
Anodizing Responsen/a — ferrous alloy; use zinc plating, phosphating, black oxide or paint instead

Common Calculations5

Specific Strength (UTS / density)calculated56 kN·m/kg
Specific Stiffness (E / density)calculated26.8 MN·m/kg
Modulus of Resiliencecalculated167 kJ/m³
Thermal Diffusivitycalculated13.5 mm²/s
Thermal Shock Resistance Indexcalculated9

Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.

Working with C25 +N

Is C25 easy to machine?

Free-machining-free grade: cold-drawn condition cuts best; normalized bar can be gummy, so use positive-rake carbide, 150–250 m/min and generous coolant to avoid built-up edge.

Can C25 be welded?

Readily welded by SMAW/GMAW/GTAW with E70xx/ER70S-x consumables; CEV ≈ 0.40 so preheat 100–150 °C only for sections over ~25 mm or high restraint.

Can C25 be formed, bent or molded?

Good cold bending and heading in +A/+N condition (bend radius ≈ 1–1.5 t); hot forging 1100–1250 °C followed by normalizing restores grain size.

What surface finishes work on C25?

No anodizing — protect with zinc/zinc-nickel plating, phosphate + oil, black oxide, e-coat or paint; can be case-hardened or induction hardened for wear surfaces.

C25 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.

ElementSpec limit (wt %)Nominal
CEN 10083-2 C25 / 1.04060.22 – 0.290.25
Si≤ 0.40.25
Mn0.4 – 0.70.55
P≤ 0.050.02
SC25E ≤0.035 S, C25R 0.020–0.040 S≤ 0.050.03
Crresidual≤ 0.40.1
Niresidual≤ 0.40.1
Moresidual; Cr+Mo+Ni ≤ 0.63≤ 0.10.02
Febalance—

C25 +N — frequently asked

What is C25 +N used for?

C25 +N is typically used for shafts, pins, forged machine parts and axles. In short: stronger than C22; weldable shaft steel; induction-hardenable carbon grade.

What is the yield strength of C25 +N?

C25 +N has a typical yield strength of 265 MPa (38.4 ksi) and a tensile strength of 440 MPa (63.8 ksi) — weaker than 92% of steel grades. Strength varies by condition: see the 6 listed tempers.

Is C25 +N easy to machine?

Reasonably — machinability is rated good (62/100, better than 89% of steel grades). Free-machining-free grade: cold-drawn condition cuts best; normalized bar can be gummy, so use positive-rake carbide, 150–250 m/min and generous coolant to avoid built-up edge.

Can C25 +N be welded?

Yes — weldability is rated excellent (88/100). Readily welded by SMAW/GMAW/GTAW with E70xx/ER70S-x consumables; CEV ≈ 0.40 so preheat 100–150 °C only for sections over ~25 mm or high restraint.

What surface finishes work on C25 +N?

No anodizing — protect with zinc/zinc-nickel plating, phosphate + oil, black oxide, e-coat or paint; can be case-hardened or induction hardened for wear surfaces.

Can C25 +N be formed, bent or molded?

Good cold bending and heading in +A/+N condition (bend radius ≈ 1–1.5 t); hot forging 1100–1250 °C followed by normalizing restores grain size.

What is the maximum service temperature of C25 +N?

C25 +N is rated for continuous use to about 400°C (752 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.

What is the difference between C25 +N and C25-IH?

+N is the default condition — standard stocked condition — uniform fine grain, balanced strength/toughness for shafts, pins and forgings. IH: selected when only local wear resistance is needed on shaft journals; maximum attainable case hardness is limited by the 0.25 % C content. Yield strength is 265 MPa in +N versus 265 MPa in IH.

Sources

  1. EN 10083-2 Steels for quenching and tempering — Non-alloy quality steels — CEN (2006)
  2. JIS G 4051 Carbon steels for machine structural use (S25C) — JISC (2016)
  3. ASTM A29/A29M — Steel bars, carbon and alloy, hot-wrought (1025) — ASTM (2020)
  4. ASM Handbook Vol.1 — Properties and Selection: Irons, Steels and High-Performance Alloys — ASM International (1990)
  5. ASM Handbook Vol.16 — Machining — ASM International (1989)
  6. Stahlschlüssel / Key to Steel 1.0406 — Verlag Stahlschlüssel (2019)
  7. Mysteel / SMM — Mysteel (2025)

Property data is compiled from published supplier and standards handbooks and normalised for comparison. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.