Steel 40NCD3 QT28-32
Hardness band · default condition
EN 40NCD3
QT28-32 = +QT 28–32 HRC
The standard stock condition: best strength/toughness/machinability balance for shafts, connecting rods and forgings.
Values for the QT28-32 condition
Other 40NCD3 tempers and conditions
40NCD3 is listed in 10 conditions; see the grade overview at 40NCD3.
Compare all 10 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Annealed | Choose for deep machining, cold sawing or before customer heat treatment; max ~241 HB per EN 10083-3. | 450 | 700 | 20 | 210 HB | — |
Hot rolled | Cheapest mill condition for stock that will be fully heat treated after rough machining. | 480 | 780 | 17 | 22 HRC | 7.8 % IACS |
Normalized | Uniform fine-grain structure for forgings before final Q&T, or for moderately stressed parts. | 520 | 830 | 18 | 24 HRC | — |
Cold drawn | Pick for close-tolerance small-diameter bar used as-supplied without further heat treatment. | 620 | 800 | 12 | 22 HRC | 7.8 % IACS |
+QT 22–26 HRC | Use for heavy sections (>100 mm), maximum toughness, or where NACE MR0175 caps hardness at 22 HRC. | 640 | 870 | 16 | 24 HRC | — |
Nitrided | Choose when a hard, low-distortion wear/fatigue skin is needed on an already tempered part (temper ≥ 570 °C required). | 780 | 980 | 12 | 55 HRC | 7.8 % IACS |
QT28-32DefaultThis page +QT 28–32 HRC | The standard stock condition: best strength/toughness/machinability balance for shafts, connecting rods and forgings. | 800 | 1,000 | 14 | 31 HRC | — |
Induction hardened | Use for journal/bearing surfaces needing 52–58 HRC wear resistance over a tough ~300 HB core. | 800 | 1,000 | 13 | 55 HRC | 7.5 % IACS |
+QT 32–36 HRC | Pick for higher-loaded shafts, gear blanks and mould bases where some machining is still needed. | 950 | 1,150 | 12 | 34 HRC | — |
+QT 36–40 HRC | Highest practical Q&T level for this lean Ni-Cr-Mo grade in thin sections; toughness and machinability drop noticeably. | 1,100 | 1,300 | 10 | 38 HRC | — |
What is 40NCD3 QT28-32?
40NCD3 QT28-32 is 40NCD3 heat treated to QT28-32 — the standard stock condition: best strength/toughness/machinability balance for shafts, connecting rods and forgings. 40NCD3 QT28-32 has a yield strength of 800 MPa (116 ksi) and a tensile strength of 1,000 MPa (145 ksi) — stronger than 86% of steel grades. Elongation at break is 14% and the elastic modulus is 210 GPa (30.5 Msi). 40NCD3 QT28-32 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).
Advantages
- High strength — 800 MPa (116 ksi), better than 86% of steel grades
- Polishes to a fine finish — 65/100, better than 78% of steel grades
Limitations
- Limited ductility — 14%, worse than 75% of steel grades
40NCD3 QT28-32 properties
Typical room-temperature values for 40NCD3 QT28-32; 14 are specific to this condition. Other listed values are 40NCD3 reference data and may not represent this condition. Bars are the position among steel grades.
Physical3
40NCD3 QT28-32 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
40NCD3 QT28-32 has a yield strength of 800 MPa (116 ksi) and a tensile strength of 1,000 MPa (145 ksi) — stronger than 86% of steel grades. Elongation at break is 14% and the elastic modulus is 210 GPa (30.5 Msi).
Thermal6
40NCD3 QT28-32 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
40NCD3 QT28-32 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 40NCD3 QT28-32 takes about 30 MJ of energy and emits 2.1 kg of CO₂ — more than 56% of steel grades. Typical recycled content is 30%.
Manufacturability6
40NCD3 QT28-32's machinability is fair (50/100, worse than 53% of steel grades); weldability fair (35/100); formability poor (30/100).
Common Calculations5
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with 40NCD3 QT28-32
Is 40NCD3 easy to machine?
Machine in the annealed or ≤32 HRC condition with coated carbide, 80–140 m/min and rigid setups; above 36 HRC switch to CBN/ceramic or grind.
Can 40NCD3 be welded?
Weldable with low-hydrogen consumables but requires 200–300 °C preheat, controlled interpass and 550–650 °C post-weld temper; welding above 32 HRC risks HAZ cracking.
Can 40NCD3 be formed, bent or molded?
Hot forge 1100–1200 °C, finish above 850 °C, then normalize; cold forming limited to mild bending in the annealed condition.
What surface finishes work on 40NCD3?
No natural corrosion protection — use phosphating + oil, black oxide, zinc or hard-chrome plating (bake at 190 °C to avoid hydrogen embrittlement); polishes well to mirror finish for mould applications.
40NCD3 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 |
|---|---|---|
| CAFNOR 40NCD3 / EN 40NiCrMo2-2 (1.6546) | 0.36 – 0.44 | 0.4 |
| Si | 0.1 – 0.4 | 0.25 |
| Mn | 0.5 – 0.9 | 0.7 |
| NiAFNOR digit 3 ≈ Ni 0.75 % | 0.4 – 0.9 | 0.75 |
| Cr | 0.35 – 0.7 | 0.5 |
| Mo | 0.15 – 0.3 | 0.2 |
| P | ≤ 0.04 | 0.02 |
| S0.020–0.040 for free-machining +S versions | ≤ 0.04 | 0.02 |
| Fe | balance | — |
40NCD3 QT28-32 — frequently asked
What is 40NCD3 QT28-32 used for?
40NCD3 QT28-32 is typically used for shafts, gears and structural forgings. In short: pre-hard shaft steel; nitrides and induction hardens; weldable with preheat.
What is the yield strength of 40NCD3 QT28-32?
40NCD3 QT28-32 has a typical yield strength of 800 MPa (116 ksi) and a tensile strength of 1,000 MPa (145 ksi) — stronger than 86% of steel grades. Strength varies by condition: see the 10 listed tempers.
Is 40NCD3 QT28-32 easy to machine?
Reasonably — machinability is rated fair (50/100, worse than 53% of steel grades). Machine in the annealed or ≤32 HRC condition with coated carbide, 80–140 m/min and rigid setups; above 36 HRC switch to CBN/ceramic or grind.
Can 40NCD3 QT28-32 be welded?
With care — weldability is rated fair (35/100). Weldable with low-hydrogen consumables but requires 200–300 °C preheat, controlled interpass and 550–650 °C post-weld temper; welding above 32 HRC risks HAZ cracking.
What surface finishes work on 40NCD3 QT28-32?
No natural corrosion protection — use phosphating + oil, black oxide, zinc or hard-chrome plating (bake at 190 °C to avoid hydrogen embrittlement); polishes well to mirror finish for mould applications.
Can 40NCD3 QT28-32 be formed, bent or molded?
Hot forge 1100–1200 °C, finish above 850 °C, then normalize; cold forming limited to mild bending in the annealed condition.
What is the maximum service temperature of 40NCD3 QT28-32?
40NCD3 QT28-32 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 40NCD3 QT28-32 and 40NCD3-HR?
QT28-32 is the default condition — the standard stock condition: best strength/toughness/machinability balance for shafts, connecting rods and forgings. HR: cheapest mill condition for stock that will be fully heat treated after rough machining. Yield strength is 800 MPa in QT28-32 versus 480 MPa in HR.
Sources
- EN 10083-3 Steels for quenching and tempering – 40NiCrMo2-2 (1.6546) — CEN (2006)
- NF A35-552 / AFNOR alloy structural steels (40NCD3) — AFNOR (1993)
- GB/T 3077 (40CrNiMoA) — SAC (2015)
- 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)
- Q&T engineering steel bar datasheets (40NiCrMo2-2 / 4340 class) — Ovako / Böhler (2022)
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.