Steel C30
EN C30 · AISI/SAE 1030 · JIS S30C · GB 30
C30 is a plain-carbon quality steel with about 0.30 % C (1.0528; also C30E, AISI 1030, JIS S30C, Ck30), sitting at the low end of the medium-carbon range.
Reference datasheet — C30 is not in the instant-quote catalog. Upload your part and an engineer will quote it in this grade or suggest the closest stocked equivalent.
Values for the N condition
C30 tempers and conditions
C30 is supplied in 11 conditions, soft to hard. N is the default FabDigit quotes; the values on this page are for it.
Compare all 11 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Hot rolled | Cheapest stock condition for weldments, brackets and parts to be machined and later heat treated. | 260 | 470 | 20 | 137 HB | — |
Spheroidize annealed | Choose for cold heading, thread rolling or severe cold forming of fasteners and forged blanks. | 290 | 440 | 35 | 120 HB | 10.5 % IACS |
Solution annealed | Softest, most stable condition for deep machining, cold bending or stress-free blanks before hardening. | 340 | 465 | 31 | 126 HB | — |
NDefault Normalized | Pick the normalized 870–900 °C air-cooled delivery and test condition for uniform fine pearlite balancing 345 MPa yield, 30% elongation and machinability before any further hardening. | 345 | 520 | 30 | 149 HB | — |
Induction hardened | Pick when journals or teeth need a hard wear surface (≈50 HRC) on a tough, ductile core. | 360 | 560 | 22 | 52 HRC | 10 % IACS |
Cold drawn | Bright, close-tolerance bar with higher yield and better surface finish; use where no further heat treatment is planned. | 440 | 525 | 12 | 149 HB | — |
Q&T 650 °C | High-temper condition when maximum toughness and machinability are wanted after hardening. | 441 | 586 | 32 | 17 HRC | — |
Q&T 540 °C | Most common quenched-and-tempered condition for general machine shafts and forgings. | 517 | 669 | 28 | 25 HRC | — |
Q&T 425 °C | Use quenching with 425 °C tempering (≈32 HRC) for loaded shafts requiring about 731 MPa tensile; hardness rises to 302 HB while elongation falls to 23%. | 579 | 731 | 23 | 32 HRC | — |
Q&T 315 °C | High strength with modest ductility for small hardened pins and levers. | 621 | 800 | 19 | 42 HRC | — |
Q&T 205 °C | Maximum hardness/wear on thin sections; low toughness, use only for small wear parts. | 648 | 848 | 17 | 50 HRC | — |
What is C30?
C30 is a plain-carbon quality steel with about 0.30 % C (1.0528; also C30E, AISI 1030, JIS S30C, Ck30), sitting at the low end of the medium-carbon range. It balances moderate strength with good machinability and formability for shafts, bolts and small forgings, and is available hot-rolled, normalized, annealed, spheroidize-annealed, cold-drawn, induction-hardened or quenched and tempered across several strength levels (QT205–QT650). Typical values are 345 MPa yield, 520 MPa tensile, 30 % elongation and 149 HB (80 HRB). It has no corrosion resistance and hardens only shallowly; step up to C35 or C45 for higher tensile strength. C30 has a density of 7.85 g/cm³ (0.284 lb/in³), heavier than 56% of steel grades. It melts at 1,425°C (2,597 °F). C30 has a yield strength of 345 MPa (50 ksi) and a tensile strength of 520 MPa (75.4 ksi) — weaker than 75% of steel grades. Elongation at break is 30% and the elastic modulus is 205 GPa (29.7 Msi).
What is C30 used for?
- shafts
- bolts
- small forgings
- machine parts
- gears (light duty)
Advantages
- Ductile — tolerates forming and impact — 30%, better than 93% of steel grades
- Conducts heat well — 50 W/m·K (28.9 BTU/hr·ft·°F), better than 87% of steel grades
- High electrical conductivity — 10 % IACS, better than 83% of steel grades
Limitations
- Low fracture toughness — 60 MPa·√m (54.6 ksi·√in), worse than 78% of steel grades
- Low strength — 345 MPa (50 ksi), worse than 75% of steel grades
C30 properties
Typical room-temperature values for C30-N; bars are the position among steel grades.
Physical3
C30 has a density of 7.85 g/cm³ (0.284 lb/in³), heavier than 56% of steel grades. It melts at 1,425°C (2,597 °F).
Mechanical16
C30 has a yield strength of 345 MPa (50 ksi) and a tensile strength of 520 MPa (75.4 ksi) — weaker than 75% of steel grades. Elongation at break is 30% and the elastic modulus is 205 GPa (29.7 Msi).
Thermal6
C30 is rated for continuous service to 400°C (752 °F). It conducts heat at 50 W/m·K (28.9 BTU/hr·ft·°F), better than 87% of steel grades. Thermal expansion is 12 µm/m·K (6.67 µin/in·°F).
Electrical3
C30 conducts electricity at 10 % IACS, better than 83% of steel grades.
Chemical & Environmental3
Corrosion resistance is not recommended (10/100), worse than 86% of steel grades.
Sustainability4
Producing a kilogram of C30 takes about 25 MJ of energy and emits 2 kg of CO₂ — less than 82% of steel grades. Typical recycled content is 30%.
Manufacturability7
C30's machinability is good (60/100, better than 83% of steel grades); weldability good (65/100); formability good (55/100).
Common Calculations5
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
Strength versus weight in the steel family
Yield strength against density for every steel grade FabDigit runs. C30 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with C30
Is C30 easy to machine?
Machines readily at ~70 % of 1212 in the normalized or cold-drawn state; annealed material can smear, so use sharp carbide, 120–200 m/min and good coolant.
Can C30 be welded?
Weldable by SMAW/GMAW with low-hydrogen consumables; at 0.30 % C preheat 100–150 °C and post-weld stress relief on thick or restrained joints to avoid HAZ cracking.
Can C30 be formed, bent or molded?
Good hot forgeability at 1100–1200 °C; cold bending needs generous radii (≥2t) and is best done annealed or spheroidized.
C30 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 |
|---|---|---|
| CGB/T 699 steel 30; AISI 1030 = 0.28-0.34 | 0.27 – 0.34 | 0.3 |
| Si | 0.17 – 0.37 | 0.25 |
| MnAISI 1030 = 0.60–0.90 | 0.5 – 0.8 | 0.65 |
| PC30E/1.1178 ≤0.025 | ≤ 0.04 | 0.02 |
| SC30E ≤0.035, C30R sulfur-treated | ≤ 0.04 | 0.02 |
| Crresidual | ≤ 0.25 | 0.05 |
| Niresidual | ≤ 0.3 | 0.05 |
| Curesidual | ≤ 0.25 | 0.05 |
| Fe | balance |
What surface finishes work on C30?
No anodizing — protect with zinc/nickel plating, phosphate + oil, black oxide or paint; takes a fine polish but will flash-rust unless coated.
Surface treatments FabDigit runs on steel parts — pick them in the quote configurator or call them out on the drawing. Each links to its datasheet in the surface-finish library (thickness, specs, call-out, material verdicts).
Organic Coating
Black / Phosphate
Thermal Spray
Equivalent designations
Standards and trade names that resolve to Steel C30 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
How much does C30 cost?
C30 is a budget-cost steel ($), cheaper than about 90% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
C30 — frequently asked
What is C30 used for?
C30 is typically used for shafts, bolts, small forgings, machine parts and gears (light duty). In short: most weldable medium carbon; good machinability and formability; lower-strength C35 alternative.
What is the yield strength of C30?
C30 has a typical yield strength of 345 MPa (50 ksi) and a tensile strength of 520 MPa (75.4 ksi) — weaker than 75% of steel grades. Strength varies by condition: see the 11 listed tempers.
Is C30 easy to machine?
Reasonably — machinability is rated good (60/100, better than 83% of steel grades). Machines readily at ~70 % of 1212 in the normalized or cold-drawn state; annealed material can smear, so use sharp carbide, 120–200 m/min and good coolant.
Can C30 be welded?
Yes — weldability is rated good (65/100). Weldable by SMAW/GMAW with low-hydrogen consumables; at 0.30 % C preheat 100–150 °C and post-weld stress relief on thick or restrained joints to avoid HAZ cracking.
What surface finishes work on C30?
No anodizing — protect with zinc/nickel plating, phosphate + oil, black oxide or paint; takes a fine polish but will flash-rust unless coated.
Can C30 be formed, bent or molded?
Good hot forgeability at 1100–1200 °C; cold bending needs generous radii (≥2t) and is best done annealed or spheroidized.
What is the maximum service temperature of C30?
C30 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 C30-N and C30-QT205?
N is the default condition — pick the normalized 870–900 °C air-cooled delivery and test condition for uniform fine pearlite balancing 345 MPa yield, 30% elongation and machinability before any further hardening. QT205: maximum hardness/wear on thin sections; low toughness, use only for small wear parts. Yield strength is 345 MPa in N versus 648 MPa in QT205.
How much does C30 cost?
C30 is a budget-cost steel ($), cheaper than about 90% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
Sources
- EN 10083-2 / EN 10277 (C30, C30E, 1.0528/1.1178) — CEN (2006)
- ASTM A29/A29M and SAE J403 (1030) — ASTM / SAE (2020)
- JIS G 4051 (S30C) — JSA (2016)
- ASM Handbook Vol.1 — Properties and Selection: Irons, Steels — ASM International (1990)
- ASM Handbook Vol.4 — Heat Treating; Vol.16 — Machining — ASM International (1991)
Property data is compiled from published supplier and standards handbooks and normalised for comparison; hardness values on non-Brinell scales are converted approximately for charting only. Manufacturability limits are FabDigit quote-engine defaults and may be relaxed by engineering review. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.