Steel C25E +NT (Normalized and tempered)
Heat-treated state
EN C25E
Choose for larger sections where full through-hardening is impossible but stress relief and consistent hardness are wanted.
Values for the +NT condition
Other C25E tempers and conditions
C25E is listed in 8 conditions; see the grade overview at C25E.
Compare all 8 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Annealed | Pick for maximum cold formability, deep drawing and pre-machining before final heat treatment. | 260 | 470 | 30 | 145 HB | — |
+QT | Same treatment on thick bar; low hardenability of C25E lowers core properties, so specify only where moderate strength suffices. | 280 | 500 | 25 | 155 HB | 10 % IACS |
Hot rolled | Cheapest stock condition for weldments and non-critical structural parts that will be machined or later heat treated. | 285 | 490 | 25 | 145 HB | — |
Normalized | Standard condition for uniform fine-grain structure, good weldability and moderate strength in larger sections. | 290 | 520 | 26 | 155 HB | — |
+NTThis page Normalized and tempered | Choose for larger sections where full through-hardening is impossible but stress relief and consistent hardness are wanted. | 300 | 540 | 26 | 160 HB | — |
+QTDefault Quenched and tempered | Default machine-component condition: best strength/toughness balance for shafts, bolts and pins up to ~40 mm section. | 380 | 610 | 23 | 180 HB | — |
Cold drawn and stress-relieved | Use when cold-drawn bar must be machined asymmetrically without bowing or distortion. | 430 | 560 | 14 | 170 HB | 10 % IACS |
Cold drawn | Pick for close tolerance, bright surface bar for automatic-lathe parts where raised yield strength is useful. | 490 | 600 | 11 | 180 HB | — |
What is C25E +NT?
C25E +NT is C25E heat treated to +NT — choose for larger sections where full through-hardening is impossible but stress relief and consistent hardness are wanted. C25E +NT has a yield strength of 300 MPa (43.5 ksi) and a tensile strength of 540 MPa (78.3 ksi) — weaker than 86% of steel grades. Elongation at break is 26% and the elastic modulus is 210 GPa (30.5 Msi). C25E +NT 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). +QT is the default condition FabDigit quotes; +NT is available on request or by drawing note.
Advantages
- Low embodied carbon — 1.9 kg CO₂/kg, better than 92% of steel grades
- Easy to machine — 62/100, better than 89% of steel grades
- High electrical conductivity — 10 % IACS, better than 83% of steel grades
- Readily welded — 85/100, better than 83% of steel grades
- Ductile — tolerates forming and impact — 26%, better than 82% of steel grades
Limitations
- Low strength — 300 MPa (43.5 ksi), worse than 86% of steel grades
C25E +NT properties
Typical room-temperature values for C25E +NT; 14 are specific to this condition. Other listed values are C25E reference data and may not represent this condition. Bars are the position among steel grades.
Physical3
C25E +NT 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).
Mechanical16
C25E +NT has a yield strength of 300 MPa (43.5 ksi) and a tensile strength of 540 MPa (78.3 ksi) — weaker than 86% of steel grades. Elongation at break is 26% and the elastic modulus is 210 GPa (30.5 Msi).
Thermal6
C25E +NT is rated for continuous service to 400°C (752 °F). It conducts heat at 48 W/m·K (27.7 BTU/hr·ft·°F), better than 79% of steel grades. Thermal expansion is 11.7 µm/m·K (6.5 µin/in·°F).
Electrical3
C25E +NT conducts electricity at 10 % IACS, better than 83% of steel grades.
Chemical & Environmental3
Corrosion resistance is not recommended (10/100), worse than 86% of steel grades.
Sustainability4
Producing a kilogram of C25E +NT takes about 25 MJ of energy and emits 1.9 kg of CO₂ — less than 82% of steel grades. Typical recycled content is 30%.
Manufacturability6
C25E +NT's machinability is good (62/100, better than 89% of steel grades); weldability excellent (85/100); formability fair (50/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with C25E +NT
Is C25E easy to machine?
Machines well at ~65 % of 1212; normalized or cold-drawn stock gives cleaner chips than annealed, use sharp positive tooling and coolant to avoid built-up edge.
Can C25E be welded?
Readily weldable by MMA/MAG/TIG; CEV ≈ 0.35–0.45 so preheat 100–150 °C for sections over ~25 mm and re-temper Q&T parts if full properties are required.
Can C25E be formed, bent or molded?
Good hot forging at 1100–850 °C; cold bending and heading practical in +A or +N condition, cold-drawn bar needs generous bend radii.
What surface finishes work on C25E?
No inherent corrosion protection — specify phosphate + oil, black oxide, zinc or nickel plating, or paint; takes a fine ground/polished finish but will rust if left bare.
C25E 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 |
|---|---|---|
| CEN 10083-2 C25E | 0.22 – 0.29 | 0.25 |
| Si | ≤ 0.4 | 0.25 |
| Mn | 0.4 – 0.7 | 0.55 |
| P | ≤ 0.03 | 0.02 |
| SC25R version: S 0.020–0.040 | ≤ 0.04 | 0.02 |
| Crresidual | ≤ 0.4 | 0.1 |
| Niresidual | ≤ 0.4 | 0.1 |
| Moresidual; Cr+Mo+Ni ≤ 0.63 | ≤ 0.1 | 0.02 |
| Fe | balance | — |
C25E +NT — frequently asked
What is C25E +NT used for?
C25E +NT is typically used for axles, shafts, bolts and machine parts. In short: quench-and-temper machine steel; stronger step above C22E; still readily weldable with preheat.
What is the yield strength of C25E +NT?
C25E +NT has a typical yield strength of 300 MPa (43.5 ksi) and a tensile strength of 540 MPa (78.3 ksi) — weaker than 86% of steel grades. Strength varies by condition: see the 8 listed tempers.
Is C25E +NT easy to machine?
Reasonably — machinability is rated good (62/100, better than 89% of steel grades). Machines well at ~65 % of 1212; normalized or cold-drawn stock gives cleaner chips than annealed, use sharp positive tooling and coolant to avoid built-up edge.
Can C25E +NT be welded?
Yes — weldability is rated excellent (85/100). Readily weldable by MMA/MAG/TIG; CEV ≈ 0.35–0.45 so preheat 100–150 °C for sections over ~25 mm and re-temper Q&T parts if full properties are required.
What surface finishes work on C25E +NT?
No inherent corrosion protection — specify phosphate + oil, black oxide, zinc or nickel plating, or paint; takes a fine ground/polished finish but will rust if left bare.
Can C25E +NT be formed, bent or molded?
Good hot forging at 1100–850 °C; cold bending and heading practical in +A or +N condition, cold-drawn bar needs generous bend radii.
What is the maximum service temperature of C25E +NT?
C25E +NT 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.
Sources
- EN 10083-2 Steels for quenching and tempering — Non-alloy steels — CEN (2006)
- EN 10277 Bright steel products — technical delivery conditions — CEN (2018)
- ASM Handbook Vol.1 — Properties and Selection: Irons, Steels — ASM International (1990)
- Stahlschlüssel / Key to Steel (1.1158 Ck25) — Verlag Stahlschlüssel (2019)
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.