Steel 30CrMnSiA-HR (Hot rolled)
Supply condition
GB 30CrMnSiA
Mill supply condition for bar and plate that will be machined then heat treated by the user.
Values for the HR condition
Other 30CrMnSiA tempers and conditions
30CrMnSiA is listed in 10 conditions; see the grade overview at 30CrMnSiA.
Compare all 10 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Solution annealed | Softest condition — choose for deep machining, cold forming or tube bending before final heat treatment. | 420 | 700 | 20 | 215 HB | — |
HRThis page Hot rolled | Mill supply condition for bar and plate that will be machined then heat treated by the user. | 480 | 780 | 16 | 23 HRC | 7.5 % IACS |
Stress relieved | Typical delivery state for welded 30CrMnSiA tube frames before final Q&T or for moderate-load weldments. | 500 | 750 | 18 | 21 HRC | 7.5 % IACS |
Normalized | Uniform fine-grain structure for forgings and pre-machining stability before Q&T. | 540 | 830 | 15 | 25 HRC | 7.4 % IACS |
Cold drawn | Close-tolerance bright bar for shafts and fasteners machined without further heat treatment. | 720 | 880 | 10 | 27 HRC | 7.3 % IACS |
Q&T 28–32 HRC (temper ~570 °C) | Tough, machinable condition for shafts and general aerospace hardware where 900–1000 MPa suffices. | 800 | 960 | 16 | 30 HRC | — |
QT1080Default Q&T | Standard GB/T 3077 delivery condition — best balance of 1100 MPa strength and toughness for structural parts. | 930 | 1,130 | 12 | 36 HRC | — |
Q&T 35–40 HRC (temper ~450–500 °C) | Higher-strength Q&T level (~1200 MPa) for landing-gear links, lugs and highly loaded bolts. | 1,080 | 1,230 | 11 | 38 HRC | — |
Q&T high strength | Aerospace high-strength condition for thin-wall welded structures and fittings; toughness and hydrogen-embrittlement margin drop sharply. | 1,350 | 1,560 | 8 | 46 HRC | — |
As-quenched | Intermediate process condition only; must be tempered promptly to avoid quench cracking. | 1,350 | 1,800 | 3 | 51 HRC | 6.5 % IACS |
What is 30CrMnSiA-HR?
30CrMnSiA-HR is 30CrMnSiA supplied in the HR condition — mill supply condition for bar and plate that will be machined then heat treated by the user. 30CrMnSiA-HR has a yield strength of 480 MPa (69.6 ksi) and a tensile strength of 780 MPa (113 ksi) — stronger than 59% of steel grades. Elongation at break is 16% and the elastic modulus is 210 GPa (30.5 Msi). 30CrMnSiA-HR 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). QT1080 is the default condition FabDigit quotes; HR is available on request or by drawing note.
Advantages
- Polishes to a fine finish — 65/100, better than 78% of steel grades
30CrMnSiA-HR properties
Typical room-temperature values for 30CrMnSiA-HR; 23 are specific to this condition. Other listed values are 30CrMnSiA reference data and may not represent this condition. Bars are the position among steel grades.
Physical3
30CrMnSiA-HR 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
30CrMnSiA-HR has a yield strength of 480 MPa (69.6 ksi) and a tensile strength of 780 MPa (113 ksi) — stronger than 59% of steel grades. Elongation at break is 16% and the elastic modulus is 210 GPa (30.5 Msi).
Thermal6
30CrMnSiA-HR is rated for continuous service to 400°C (752 °F). It conducts heat at 42 W/m·K (24.3 BTU/hr·ft·°F), worse than 56% of steel grades. Thermal expansion is 11.3 µm/m·K (6.28 µin/in·°F).
Electrical3
30CrMnSiA-HR conducts electricity at 7.5 % IACS, worse than 67% of steel grades.
Chemical & Environmental3
Corrosion resistance is not recommended (12/100), worse than 53% of steel grades.
Sustainability4
Producing a kilogram of 30CrMnSiA-HR takes about 34 MJ of energy and emits 2.4 kg of CO₂ — more than 82% of steel grades. Typical recycled content is 25%.
Manufacturability7
30CrMnSiA-HR's machinability is fair (50/100, worse than 53% of steel grades); weldability good (60/100); formability fair (40/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with 30CrMnSiA-HR
Is 30CrMnSiA easy to machine?
Machine in the annealed/normalized state (≈45–60 % of AISI 1212); above 35 HRC use carbide or CBN with rigid setups and reduced feed; leave grinding stock for post-Q&T distortion.
Can 30CrMnSiA be welded?
Good TIG/MIG/resistance weldability up to ~4 mm; preheat 150–300 °C for thick sections, use ER80S-D2/matching filler, and temper or fully re-Q&T after welding to avoid martensitic HAZ cracking.
Can 30CrMnSiA be formed, bent or molded?
Cold bend and roll only in the annealed condition (min bend radius ≈2t); hot forge at 1150–850 °C then normalize; oil quench from 860–890 °C, temper 200–600 °C to the required strength level.
What surface finishes work on 30CrMnSiA?
No corrosion resistance bare — apply Cd or Zn plating, phosphate + primer, or hard chrome; bake at 190 °C for 8–23 h after plating above 1000 MPa to relieve hydrogen embrittlement; shot peening markedly improves fatigue life.
30CrMnSiA 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 | 0.28 – 0.34 | 0.31 |
| Si | 0.9 – 1.2 | 1.05 |
| Mn | 0.8 – 1.1 | 0.95 |
| Cr | 0.8 – 1.1 | 0.95 |
| Niresidual | ≤ 0.3 | 0.1 |
| Curesidual | ≤ 0.25 | 0.1 |
| Moresidual, not intentionally added | ≤ 0.1 | — |
| P'A' high-grade limit | ≤ 0.03 | 0.01 |
| S'A' high-grade limit | ≤ 0.03 | 0.01 |
| Fe | balance | — |
30CrMnSiA-HR — frequently asked
What is 30CrMnSiA-HR used for?
30CrMnSiA-HR is typically used for aircraft parts, high-strength fasteners and landing gear components. In short: aerospace-quality 4130 equivalent; weldable up to 4 mm; tempers to 1470 MPa.
What is the yield strength of 30CrMnSiA-HR?
30CrMnSiA-HR has a typical yield strength of 480 MPa (69.6 ksi) and a tensile strength of 780 MPa (113 ksi) — stronger than 59% of steel grades. Strength varies by condition: see the 10 listed tempers.
Is 30CrMnSiA-HR easy to machine?
Reasonably — machinability is rated fair (50/100, worse than 53% of steel grades). Machine in the annealed/normalized state (≈45–60 % of AISI 1212); above 35 HRC use carbide or CBN with rigid setups and reduced feed; leave grinding stock for post-Q&T distortion.
Can 30CrMnSiA-HR be welded?
Yes — weldability is rated good (60/100). Good TIG/MIG/resistance weldability up to ~4 mm; preheat 150–300 °C for thick sections, use ER80S-D2/matching filler, and temper or fully re-Q&T after welding to avoid martensitic HAZ cracking.
What surface finishes work on 30CrMnSiA-HR?
No corrosion resistance bare — apply Cd or Zn plating, phosphate + primer, or hard chrome; bake at 190 °C for 8–23 h after plating above 1000 MPa to relieve hydrogen embrittlement; shot peening markedly improves fatigue life.
Can 30CrMnSiA-HR be formed, bent or molded?
Cold bend and roll only in the annealed condition (min bend radius ≈2t); hot forge at 1150–850 °C then normalize; oil quench from 860–890 °C, temper 200–600 °C to the required strength level.
What is the maximum service temperature of 30CrMnSiA-HR?
30CrMnSiA-HR 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 30CrMnSiA-QT1080 and 30CrMnSiA-A?
QT1080 is the default condition — standard GB/T 3077 delivery condition — best balance of 1100 MPa strength and toughness for structural parts. A: softest condition — choose for deep machining, cold forming or tube bending before final heat treatment. Yield strength is 930 MPa in QT1080 versus 420 MPa in A.
Sources
- GOST 4543 (30ХГСА structural alloy steel) — Gosstandart (2016)
- ASM Handbook Vol.1: Properties and Selection — Irons, Steels, and High-Performance Alloys — ASM International (1990)
- MMPDS-17 (AISI 4130/4135 low-alloy steel chapters, used as analogue) — Battelle/FAA (2022)
- (30CrMnSiA) — Mysteel / 1688 (2025)
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.