Steel EN24T-CR (Cold rolled)
Supply condition
BS EN24T · AISI/SAE 4340
Flat product with tight thickness and improved surface for machined plates and blanks.
Values for the CR condition
Other EN24T tempers and conditions
EN24T is listed in 13 conditions; see the grade overview at EN24T.
Compare all 13 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
soft, spheroidised/full annealed for machining | Pick when the part must be heavily machined or cold worked before its own hardening cycle. | 460 | 700 | 22 | 210 HB | — |
HRDefault Hot rolled | Cheapest mill condition for parts that will be fully heat treated after rough machining. | 560 | 900 | 16 | 26 HRC | 7.8 % IACS |
Quenched and tempered | The standard stocked EN24T condition — best all-round strength/toughness balance and still machinable. | 750 | 930 | 17 | 29 HRC | — |
Q&T + gas/plasma nitrided case | Add when wear resistance and fatigue life of a Q&T core are needed without distortion from re-hardening. | 750 | 930 | 15 | 55 HRC | 7.8 % IACS |
CRThis page Cold rolled | Flat product with tight thickness and improved surface for machined plates and blanks. | 780 | 940 | 14 | 30 HRC | 7.8 % IACS |
Cold drawn | Choose for bright, straight, close-tolerance shafting that needs little finish machining. | 800 | 950 | 14 | 30 HRC | 7.8 % IACS |
air cooled from ~870 °C | Grain refinement before final hardening; this air-hardening grade comes out hard, so a subcritical temper is usually added. | 800 | 1,150 | 12 | 36 HRC | — |
Q&T Condition U | One step above T when slightly higher strength is needed with almost the same toughness. | 820 | 1,000 | 15 | 31 HRC | 7.8 % IACS |
Q&T Condition V | Typical for heavier-duty shafts, gears and high-tensile fasteners. | 900 | 1,075 | 14 | 34 HRC | — |
Q&T Condition W | High-strength condition for aircraft/heavy-vehicle components; machining becomes noticeably harder. | 1,000 | 1,150 | 13 | 36 HRC | — |
Q&T Condition X | Used where very high tensile strength is required and toughness/machinability can be traded away. | 1,070 | 1,230 | 12 | 40 HRC | — |
Q&T Condition Y | Near the practical strength ceiling for machined parts; grinding often replaces turning. | 1,150 | 1,300 | 11 | 42 HRC | — |
Q&T Condition Z | Maximum-strength low-temper condition for small sections only; low toughness and high hydrogen-embrittlement risk. | 1,320 | 1,600 | 8 | 48 HRC | — |
What is EN24T-CR?
EN24T-CR is EN24T supplied in the CR condition — flat product with tight thickness and improved surface for machined plates and blanks. EN24T-CR has a yield strength of 780 MPa (113 ksi) and a tensile strength of 940 MPa (136 ksi) — stronger than 86% of steel grades. Elongation at break is 14% and the elastic modulus is 205 GPa (29.7 Msi). EN24T-CR 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). HR is the default condition FabDigit quotes; CR is available on request or by drawing note.
Advantages
- Polishes to a fine finish — 70/100, better than 87% of steel grades
- High strength — 780 MPa (113 ksi), better than 86% of steel grades
Limitations
- Limited formability — 15/100, worse than 87% of steel grades
- Difficult to weld — 22/100, worse than 81% of steel grades
- Limited ductility — 14%, worse than 75% of steel grades
EN24T-CR properties
Typical room-temperature values for EN24T-CR; 22 are specific to this condition. Other listed values are EN24T reference data and may not represent this condition. Bars are the position among steel grades.
Physical3
EN24T-CR 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).
Mechanical16
EN24T-CR has a yield strength of 780 MPa (113 ksi) and a tensile strength of 940 MPa (136 ksi) — stronger than 86% of steel grades. Elongation at break is 14% and the elastic modulus is 205 GPa (29.7 Msi).
Thermal6
EN24T-CR is rated for continuous service to 400°C (752 °F). It conducts heat at 44 W/m·K (25.4 BTU/hr·ft·°F), better than 57% of steel grades. Thermal expansion is 12.3 µm/m·K (6.83 µin/in·°F).
Electrical3
EN24T-CR 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 EN24T-CR takes about 32 MJ of energy and emits 2.3 kg of CO₂ — more than 70% of steel grades. Typical recycled content is 35%.
Manufacturability7
EN24T-CR's machinability is fair (48/100, worse than 57% of steel grades); weldability poor (22/100); formability poor (15/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with EN24T-CR
Is EN24T easy to machine?
Machinable in T condition with carbide at ~90–140 m/min, rigid setups and positive rake; above ~350 HB switch to CBN/ceramic or grind.
Can EN24T be welded?
Poor weldability (CE ≈ 0.9–1.0): use low-hydrogen consumables, preheat 250–350 °C, interpass control and immediate PWHT/temper below the original tempering temperature.
Can EN24T be formed, bent or molded?
Hot forge 1100–1200 °C finishing above 900 °C then slow cool or normalise; cold forming is not practical in Q&T conditions.
What surface finishes work on EN24T?
Not anodizable — protect with zinc/nickel plating, black oxide, phosphate or paint; bake 190–210 °C after plating to avoid hydrogen embrittlement, or nitride for wear surfaces.
EN24T 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 |
| Ni | 1.3 – 1.7 | 1.5 |
| Cr | 1 – 1.4 | 1.2 |
| Mo | 0.2 – 0.35 | 0.28 |
| P | ≤ 0.04 | — |
| Smax; 817M40S variant is resulphurised for machinability | ≤ 0.04 | — |
| Fe | balance | — |
EN24T-CR — frequently asked
What is EN24T-CR used for?
EN24T-CR is typically used for drive shafts, forged industrial parts, gearbox shafts and pinions, high-strength bolts and studs, crankshafts and axles and torsion bars. In short: Q&T Ni-Cr-Mo bar.
What is the yield strength of EN24T-CR?
EN24T-CR has a typical yield strength of 780 MPa (113 ksi) and a tensile strength of 940 MPa (136 ksi) — stronger than 86% of steel grades. Strength varies by condition: see the 13 listed tempers.
Is EN24T-CR easy to machine?
Reasonably — machinability is rated fair (48/100, worse than 57% of steel grades). Machinable in T condition with carbide at ~90–140 m/min, rigid setups and positive rake; above ~350 HB switch to CBN/ceramic or grind.
Can EN24T-CR be welded?
Not readily — weldability is rated poor (22/100). Poor weldability (CE ≈ 0.9–1.0): use low-hydrogen consumables, preheat 250–350 °C, interpass control and immediate PWHT/temper below the original tempering temperature.
What surface finishes work on EN24T-CR?
Not anodizable — protect with zinc/nickel plating, black oxide, phosphate or paint; bake 190–210 °C after plating to avoid hydrogen embrittlement, or nitride for wear surfaces.
Can EN24T-CR be formed, bent or molded?
Hot forge 1100–1200 °C finishing above 900 °C then slow cool or normalise; cold forming is not practical in Q&T conditions.
What is the maximum service temperature of EN24T-CR?
EN24T-CR 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 EN24T-HR and EN24T-CD?
HR is the default condition — cheapest mill condition for parts that will be fully heat treated after rough machining. CD: choose for bright, straight, close-tolerance shafting that needs little finish machining. Yield strength is 560 MPa in HR versus 800 MPa in CD.
Can FabDigit make parts in EN24T-CR?
Yes — EN24T-CR 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 970-1: Wrought steels — 817M40 (EN24) mechanical condition T–Z — BSI (1991)
- EN 10083-3 / GB/T 3077 — 40CrNiMoA (34CrNiMo6 family) alloy structural steel — CEN / SAC (2015)
- ASM Handbook Vol.1: Properties and Selection — Irons, Steels and High-Performance Alloys (4340) — ASM International (1990)
- ASM Handbook Vol.19: Fatigue and Fracture — ASM International (1996)
- Machinery's Handbook — machinability ratings — Industrial Press (2020)
- 817M40 / EN24T engineering steel datasheets — West Yorkshire Steel / Interlloy / Smiths Metal Centres (2023)
- 40CrNiMoA — Mysteel / 1688 (2026)
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.