Steel En26 Nitrided
Finish state
Choose when a wear-resistant, fatigue-strengthening surface is needed on a tough core with negligible distortion.
Values for the Nitrided condition
Other En26 tempers and conditions
En26 is listed in 9 conditions; see the grade overview at En26.
Compare all 9 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
fully softened for machining/forming | Pick for rough machining of large sections before hardening, or for cold forming. | 450 | 700 | 22 | 205 HB | — |
air cooled from ~870 °C | Use to refine grain and homogenise forgings prior to hardening; not a service condition for this grade. | 620 | 950 | 14 | 29 HRC | 7.3 % IACS |
TDefault Q&T condition T | Most commonly stocked bar condition — best toughness/strength balance for shafts and general engineering. | 730 | 930 | 16 | 28 HRC | — |
NitridedThis page Q&T + gas nitrided case | Choose when a wear-resistant, fatigue-strengthening surface is needed on a tough core with negligible distortion. | 790 | 1,000 | 12 | 60 HRC | 7.2 % IACS |
Q&T condition V | Common for medium-large gears and heavily loaded shafts. | 850 | 1,075 | 14 | 34 HRC | — |
Solution heat treated (unstable) | High-strength condition for compact, heavily stressed shafts and pins. | 940 | 1,150 | 13 | 36 HRC | — |
Q&T condition X | For high-duty fasteners and aerospace-type parts where toughness can be traded for strength. | 1,030 | 1,225 | 12 | 40 HRC | — |
Q&T condition Y | Very high strength; specify only where impact loading is limited and stress raisers are controlled. | 1,100 | 1,310 | 11 | 42 HRC | — |
Q&T condition Z | Maximum-strength low-temperature-tempered condition for small sections; low toughness and hydrogen-embrittlement sensitive. | 1,350 | 1,620 | 8 | 49 HRC | — |
What is En26 Nitrided?
En26 Nitrided is En26 supplied in the Nitrided condition — choose when a wear-resistant, fatigue-strengthening surface is needed on a tough core with negligible distortion. En26 Nitrided has a yield strength of 790 MPa (115 ksi) and a tensile strength of 1,000 MPa (145 ksi) — stronger than 86% of steel grades. Elongation at break is 12% and the elastic modulus is 207 GPa (30 Msi). En26 Nitrided has a density of 7.83 g/cm³ (0.283 lb/in³), lighter than 80% of steel grades. It melts at 1,420°C (2,588 °F). T is the default condition FabDigit quotes; Nitrided is available on request or by drawing note.
Advantages
- High service temperature — 480°C (896 °F), better than 88% of steel grades
- Polishes to a fine finish — 70/100, better than 87% of steel grades
- High strength — 790 MPa (115 ksi), better than 86% of steel grades
Limitations
- Difficult to machine — 8/100, worse than 100% of steel grades
- Difficult to weld — 5/100, worse than 100% of steel grades
- Limited formability — 5/100, worse than 99% of steel grades
- Limited ductility — 12%, worse than 84% of steel grades
En26 Nitrided properties
Typical room-temperature values for En26 Nitrided; 22 are specific to this condition. Other listed values are En26 reference data and may not represent this condition. Bars are the position among steel grades.
Physical3
En26 Nitrided has a density of 7.83 g/cm³ (0.283 lb/in³), lighter than 80% of steel grades. It melts at 1,420°C (2,588 °F).
Mechanical16
En26 Nitrided has a yield strength of 790 MPa (115 ksi) and a tensile strength of 1,000 MPa (145 ksi) — stronger than 86% of steel grades. Elongation at break is 12% and the elastic modulus is 207 GPa (30 Msi).
Thermal6
En26 Nitrided is rated for continuous service to 480°C (896 °F). It conducts heat at 42 W/m·K (24.3 BTU/hr·ft·°F), worse than 56% of steel grades. Thermal expansion is 12.3 µm/m·K (6.83 µin/in·°F).
Electrical3
En26 Nitrided conducts electricity at 7.2 % IACS, worse than 71% of steel grades.
Chemical & Environmental3
Corrosion resistance is poor (18/100), better than 83% of steel grades.
Sustainability4
Producing a kilogram of En26 Nitrided takes about 34 MJ of energy and emits 2.4 kg of CO₂ — more than 82% of steel grades. Typical recycled content is 25%.
Manufacturability8
En26 Nitrided's machinability is not recommended (8/100, worse than 100% of steel grades); weldability not recommended (5/100); formability not recommended (5/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with En26 Nitrided
Is En26 easy to machine?
Machine in annealed or condition T/U with rigid setups, sharp carbide and generous coolant; above ~350 HB expect low tool life — consider grinding or finish-machining before final temper.
Can En26 be welded?
Poor weldability (CE ≈ 0.9): preheat 250–350 °C, low-hydrogen electrodes, and immediate post-weld temper below the original tempering temperature; avoid welding in conditions X/Y/Z.
Can En26 be formed, bent or molded?
Hot forge 1150–850 °C then slow cool/anneal; cold forming only in the annealed state with generous bend radii.
What surface finishes work on En26?
Not anodisable — protect with zinc/cadmium plating (bake at 190–200 °C to relieve hydrogen), black oxide, phosphate + oil, or nitride for wear surfaces; polishes to a fine finish when hardened.
En26 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 |
|---|---|---|
| C | 0.36 – 0.44 | 0.4 |
| Si | 0.1 – 0.35 | 0.25 |
| Mn | 0.45 – 0.7 | 0.6 |
| P | ≤ 0.04 | — |
| Smax; 826M40 free-cutting variants allow 0.15–0.25 S | ≤ 0.04 | — |
| Ni | 2.3 – 2.8 | 2.55 |
| Cr | 0.5 – 0.8 | 0.65 |
| Mo | 0.45 – 0.65 | 0.55 |
| Fe | balance | — |
En26 Nitrided — frequently asked
What is En26 Nitrided used for?
En26 Nitrided is typically used for large shafts, gears, crankshafts and aerospace fasteners. In short: highest-hardenability En Ni-Cr-Mo; stronger alternative to En25; poor weldability, CE ≈ 0.9.
What is the yield strength of En26 Nitrided?
En26 Nitrided has a typical yield strength of 790 MPa (115 ksi) and a tensile strength of 1,000 MPa (145 ksi) — stronger than 86% of steel grades. Strength varies by condition: see the 9 listed tempers.
Is En26 Nitrided easy to machine?
Not especially — machinability is rated not recommended (8/100, worse than 100% of steel grades). Machine in annealed or condition T/U with rigid setups, sharp carbide and generous coolant; above ~350 HB expect low tool life — consider grinding or finish-machining before final temper.
Can En26 Nitrided be welded?
Not readily — weldability is rated not recommended (5/100). Poor weldability (CE ≈ 0.9): preheat 250–350 °C, low-hydrogen electrodes, and immediate post-weld temper below the original tempering temperature; avoid welding in conditions X/Y/Z.
What surface finishes work on En26 Nitrided?
Not anodisable — protect with zinc/cadmium plating (bake at 190–200 °C to relieve hydrogen), black oxide, phosphate + oil, or nitride for wear surfaces; polishes to a fine finish when hardened.
Can En26 Nitrided be formed, bent or molded?
Hot forge 1150–850 °C then slow cool/anneal; cold forming only in the annealed state with generous bend radii.
What is the maximum service temperature of En26 Nitrided?
En26 Nitrided is rated for continuous use to about 480°C (896 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between En26-T and En26-Z?
T is the default condition — most commonly stocked bar condition — best toughness/strength balance for shafts and general engineering. Z: maximum-strength low-temperature-tempered condition for small sections; low toughness and hydrogen-embrittlement sensitive. Yield strength is 730 MPa in T versus 1,350 MPa in Z.
Sources
- BS 970-1: Wrought steels — 826M40 (En26) — BSI (1991)
- ASM Handbook Vol.1 — Properties and Selection: Irons, Steels and High-Performance Alloys — ASM International (1990)
- ASM Handbook Vol.19 — Fatigue and Fracture — ASM International (1996)
- MMPDS — 4340 low-alloy steel design allowables — Battelle/FAA (2022)
- GB/T 3077 — 40CrNiMoA (2015)
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.