Steel 38CrMoAlA-CD (Cold drawn)
Supply condition
GB 38CrMoAlA · EN 38CrMoAl A, 41CrAlMo7-10
Pick for small-diameter precision shafting where dimensional accuracy matters more than core strength.
Values for the CD condition
Other 38CrMoAlA tempers and conditions
38CrMoAlA is listed in 8 conditions; see the grade overview at 38CrMoAlA.
Compare all 8 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Annealed (softened, ≤229 HB) | Pick for rough machining of large blanks or for stock that will be fully heat treated afterwards. | 450 | 720 | 20 | 210 HB | — |
Hot rolled | Cheapest mill condition for forging or re-heat-treatment; hardness and structure not controlled for machining. | 550 | 850 | 16 | 25 HRC | 8.2 % IACS |
Normalized (~930–950 °C, air cooled) | Use to homogenise forgings and refine grain before quenching; not a final service condition. | 620 | 900 | 15 | 27 HRC | 8 % IACS |
CDThis page Cold drawn | Pick for small-diameter precision shafting where dimensional accuracy matters more than core strength. | 700 | 850 | 10 | 25 HRC | 8 % IACS |
Q&T to 28–32 HRC | Specify when impact toughness and machinability of the finished part outweigh core strength. | 830 | 980 | 17 | 30 HRC | — |
Q&TDefault Quenched and tempered | Standard supply and pre-nitriding condition: tough ~1000 MPa core that stays dimensionally stable during nitriding. | 880 | 1,030 | 16 | 32 HRC | — |
Q&T + gas/ion nitrided | The service condition for this grade: extreme surface hardness and wear/scuffing resistance on a tough Q&T core. | 880 | 1,030 | 14 | 68 HRC | — |
Q&T to 32–36 HRC | Choose for heavily loaded screws, spindles and gears where core strength governs before nitriding. | 950 | 1,100 | 14 | 34 HRC | — |
What is 38CrMoAlA-CD?
38CrMoAlA-CD is 38CrMoAlA supplied in the CD condition — pick for small-diameter precision shafting where dimensional accuracy matters more than core strength. 38CrMoAlA-CD has a yield strength of 700 MPa (102 ksi) and a tensile strength of 850 MPa (123 ksi) — stronger than 81% of steel grades. Elongation at break is 10% and the elastic modulus is 210 GPa (30.5 Msi). 38CrMoAlA-CD has a density of 7.8 g/cm³ (0.282 lb/in³), lighter than 87% of steel grades. It melts at 1,420°C (2,588 °F). Q&T is the default condition FabDigit quotes; CD is available on request or by drawing note.
Advantages
- Polishes to a fine finish — 70/100, better than 87% of steel grades
- High strength — 700 MPa (102 ksi), better than 81% of steel grades
Limitations
- Limited ductility — 10%, worse than 91% of steel grades
- Difficult to weld — 20/100, worse than 84% of steel grades
- Low fracture toughness — 55 MPa·√m (50.1 ksi·√in), worse than 82% of steel grades
- Limited formability — 20/100, worse than 80% of steel grades
- Poor heat conductor — 35 W/m·K (20.2 BTU/hr·ft·°F), worse than 75% of steel grades
38CrMoAlA-CD properties
Typical room-temperature values for 38CrMoAlA-CD; 23 are specific to this condition. Other listed values are 38CrMoAlA reference data and may not represent this condition. Bars are the position among steel grades.
Physical3
38CrMoAlA-CD has a density of 7.8 g/cm³ (0.282 lb/in³), lighter than 87% of steel grades. It melts at 1,420°C (2,588 °F).
Mechanical16
38CrMoAlA-CD has a yield strength of 700 MPa (102 ksi) and a tensile strength of 850 MPa (123 ksi) — stronger than 81% of steel grades. Elongation at break is 10% and the elastic modulus is 210 GPa (30.5 Msi).
Thermal6
38CrMoAlA-CD is rated for continuous service to 350°C (662 °F). It conducts heat at 35 W/m·K (20.2 BTU/hr·ft·°F), worse than 75% of steel grades. Thermal expansion is 11.9 µm/m·K (6.61 µin/in·°F).
Electrical3
38CrMoAlA-CD conducts electricity at 8 % IACS, better than 55% of steel grades.
Chemical & Environmental3
Corrosion resistance is not recommended (12/100), worse than 53% of steel grades.
Sustainability4
Producing a kilogram of 38CrMoAlA-CD takes about 34 MJ of energy and emits 2.3 kg of CO₂ — more than 82% of steel grades. Typical recycled content is 30%.
Manufacturability8
38CrMoAlA-CD's machinability is fair (50/100, worse than 53% of steel grades); weldability poor (20/100); formability poor (20/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with 38CrMoAlA-CD
Is 38CrMoAlA easy to machine?
Machine in the Q&T condition with rigid setups, coated carbide and generous coolant; finish-grind after nitriding since the case is essentially unmachinable.
Can 38CrMoAlA be welded?
Poor weldability — high Al/Cr/Mo and 0.38 % C give hardening and cracking; if unavoidable use 250–350 °C preheat, low-hydrogen filler and immediate stress relief below the temper temperature, and never weld a nitrided surface.
Can 38CrMoAlA be formed, bent or molded?
Hot forge at 1150–850 °C followed by slow cooling and annealing; cold forming is impractical except mild straightening of soft bar.
What surface finishes work on 38CrMoAlA?
Stress relieve at 550–600 °C before nitriding, then gas or plasma nitride at 500–540 °C for 0.3–0.6 mm case; finish by lapping/polishing or light grinding, and oil, phosphate or blacken any non-nitrided surface for rust protection.
38CrMoAlA 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 | 0.35 – 0.42 | 0.38 |
| Si | 0.2 – 0.45 | 0.3 |
| Mn | 0.3 – 0.6 | 0.45 |
| Cr | 1.35 – 1.65 | 1.5 |
| Mo | 0.15 – 0.25 | 0.2 |
| Alnitride former — key to the AlN-rich hard case | 0.7 – 1.1 | 0.9 |
| Niresidual | ≤ 0.3 | — |
| Curesidual | ≤ 0.2 | — |
| PA grade = high quality, restricted P | ≤ 0.03 | — |
| SA grade = high quality, restricted S | ≤ 0.03 | — |
| Fe | balance | — |
38CrMoAlA-CD — frequently asked
What is 38CrMoAlA-CD used for?
38CrMoAlA-CD is typically used for nitrided precision shafts, extruder and injection screws, gears and pinions, machine tool spindles, valve stems and spindles and hydraulic piston rods. In short: nitridable Cr-Mo-Al bar.
What is the yield strength of 38CrMoAlA-CD?
38CrMoAlA-CD has a typical yield strength of 700 MPa (102 ksi) and a tensile strength of 850 MPa (123 ksi) — stronger than 81% of steel grades. Strength varies by condition: see the 8 listed tempers.
Is 38CrMoAlA-CD easy to machine?
Reasonably — machinability is rated fair (50/100, worse than 53% of steel grades). Machine in the Q&T condition with rigid setups, coated carbide and generous coolant; finish-grind after nitriding since the case is essentially unmachinable.
Can 38CrMoAlA-CD be welded?
Not readily — weldability is rated poor (20/100). Poor weldability — high Al/Cr/Mo and 0.38 % C give hardening and cracking; if unavoidable use 250–350 °C preheat, low-hydrogen filler and immediate stress relief below the temper temperature, and never weld a nitrided surface.
What surface finishes work on 38CrMoAlA-CD?
Stress relieve at 550–600 °C before nitriding, then gas or plasma nitride at 500–540 °C for 0.3–0.6 mm case; finish by lapping/polishing or light grinding, and oil, phosphate or blacken any non-nitrided surface for rust protection.
Can 38CrMoAlA-CD be formed, bent or molded?
Hot forge at 1150–850 °C followed by slow cooling and annealing; cold forming is impractical except mild straightening of soft bar.
What is the maximum service temperature of 38CrMoAlA-CD?
38CrMoAlA-CD is rated for continuous use to about 350°C (662 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between 38CrMoAlA Q&T and 38CrMoAlA-HR?
Q&T is the default condition — standard supply and pre-nitriding condition: tough ~1000 MPa core that stays dimensionally stable during nitriding. HR: cheapest mill condition for forging or re-heat-treatment; hardness and structure not controlled for machining. Yield strength is 880 MPa in Q&T versus 550 MPa in HR.
Can FabDigit make parts in 38CrMoAlA-CD?
Yes — 38CrMoAlA-CD 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
- ASM Handbook Vol.1: Properties and Selection: Irons, Steels, and High-Performance Alloys — ASM International (1990)
- ASM Handbook Vol.4A: Steel Heat Treating Fundamentals and Processes (nitriding steels) — ASM International (2013)
- 38CrMoAl / 34CrAlMo5 nitriding steel bar datasheet — / Böhler (2022)
- (38CrMoAlA) — 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.