Steel S30C
JIS S30C
S30C is a Japanese medium-carbon machine-structural steel comparable to SAE 1030, used where moderate strength and good machinability are both required.
Reference datasheet — S30C 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
S30C tempers and conditions
S30C is supplied in 7 conditions, soft to hard. N is the default FabDigit quotes; the values on this page are for it.
Compare all 7 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Solution annealed | Softest condition; pick for deep machining, cold forming or before subsequent heat treatment. | 280 | 465 | 31 | 137 HB | — |
Hot rolled | Cheapest stock form for weldments and rough-machined parts where dimensional accuracy is not critical. | 310 | 500 | 27 | 149 HB | — |
NDefault Normalized | Standard JIS reference condition: uniform fine-grain structure, balanced strength/toughness for general machine parts. | 330 | 520 | 26 | 156 HB | — |
Induction hardened | Select for shafts and journals needing a wear-resistant 45–55 HRC skin with a tough unhardened core. | 330 | 520 | 20 | 50 HRC | 49 W/m·K |
Q&T | Water/oil quench + high tempering for tough shafts and connecting parts; best strength-toughness balance in sections ≤ 40 mm. | 470 | 650 | 22 | 195 HB | — |
Cold drawn | Choose for close-tolerance shafts and screw-machine parts needing higher yield and good surface without heat treatment. | 495 | 590 | 14 | 179 HB | — |
Q&T | For higher-strength small-section shafts, pins and studs; limited by the grade's low hardenability (thin sections only). | 690 | 850 | 17 | 26 HRC | — |
What is S30C?
S30C is a Japanese medium-carbon machine-structural steel comparable to SAE 1030, used where moderate strength and good machinability are both required. It is supplied annealed, hot-rolled, normalized and cold-drawn, with quenched-and-tempered conditions to 600 and 450 MPa class and induction-hardened surfaces available. Normalized properties are 330 MPa yield, 520 MPa tensile and 26 % elongation at 156 HB, with service to 400 °C and a weldability score of 65. Carbon equivalent near 0.45 means preheat is needed on thicker welds, and cold bending is restricted; S25C is the easier-welding choice, S35C the stronger one. S30C 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). S30C has a yield strength of 330 MPa (47.9 ksi) and a tensile strength of 520 MPa (75.4 ksi) — weaker than 78% of steel grades. Elongation at break is 26% and the elastic modulus is 205 GPa (29.7 Msi).
What is S30C used for?
- shafts
- bolts
- levers
- structural pins
Advantages
- Conducts heat well — 51 W/m·K (29.5 BTU/hr·ft·°F), better than 92% of steel grades
- Easy to machine — 62/100, better than 89% of steel grades
- High electrical conductivity — 10 % IACS, better than 83% of steel grades
- Ductile — tolerates forming and impact — 26%, better than 82% of steel grades
Limitations
- Low strength — 330 MPa (47.9 ksi), worse than 78% of steel grades
- Low fracture toughness — 65 MPa·√m (59.2 ksi·√in), worse than 75% of steel grades
S30C properties
Typical room-temperature values for S30C-N; bars are the position among steel grades.
Physical3
S30C 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
S30C has a yield strength of 330 MPa (47.9 ksi) and a tensile strength of 520 MPa (75.4 ksi) — weaker than 78% of steel grades. Elongation at break is 26% and the elastic modulus is 205 GPa (29.7 Msi).
Thermal6
S30C is rated for continuous service to 400°C (752 °F). It conducts heat at 51 W/m·K (29.5 BTU/hr·ft·°F), better than 92% of steel grades. Thermal expansion is 11.7 µm/m·K (6.5 µin/in·°F).
Electrical3
S30C 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 S30C takes about 25 MJ of energy and emits 2 kg of CO₂ — less than 82% of steel grades. Typical recycled content is 30%.
Manufacturability8
S30C's machinability is good (62/100, better than 89% of steel grades); weldability good (65/100); formability fair (50/100).
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. S30C is highlighted; hover a dot for its name, or open the interactive family chart.
Working with S30C
Is S30C easy to machine?
Machines cleanly at ~70 % of 1212; normalized or cold-drawn condition gives the best chip control, annealed material tends to smear.
Can S30C be welded?
Weldable with low-hydrogen electrodes; carbon equivalent ~0.45 so preheat 100–150 °C and post-weld stress relief for sections over ~25 mm.
Can S30C be formed, bent or molded?
Hot forges readily at 1100–1200 °C; cold bending is limited — use generous radii or anneal first.
S30C 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 |
|---|---|---|
| CJIS G4051 | 0.27 – 0.33 | 0.3 |
| Si | 0.15 – 0.35 | 0.25 |
| Mn | 0.6 – 0.9 | 0.75 |
| P | ≤ 0.03 | |
| S | ≤ 0.04 | |
| Curesidual max | ≤ 0.3 | |
| Niresidual max | ≤ 0.2 | |
| Crresidual max; Ni+Cr ≤ 0.35 | ≤ 0.2 | |
| Fe | balance |
What surface finishes work on S30C?
No inherent corrosion protection — apply phosphate + oil, black oxide, zinc plating or paint; takes hard chrome and induction-hardened ground finishes well.
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 S30C in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
How much does S30C cost?
S30C 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.
S30C — frequently asked
What is S30C used for?
S30C is typically used for shafts, bolts, levers and structural pins. In short: mid-range strength and machinability; weldable with preheat; induction-hardenable shaft steel.
What is the yield strength of S30C?
S30C has a typical yield strength of 330 MPa (47.9 ksi) and a tensile strength of 520 MPa (75.4 ksi) — weaker than 78% of steel grades. Strength varies by condition: see the 7 listed tempers.
Is S30C easy to machine?
Reasonably — machinability is rated good (62/100, better than 89% of steel grades). Machines cleanly at ~70 % of 1212; normalized or cold-drawn condition gives the best chip control, annealed material tends to smear.
Can S30C be welded?
Yes — weldability is rated good (65/100). Weldable with low-hydrogen electrodes; carbon equivalent ~0.45 so preheat 100–150 °C and post-weld stress relief for sections over ~25 mm.
What surface finishes work on S30C?
No inherent corrosion protection — apply phosphate + oil, black oxide, zinc plating or paint; takes hard chrome and induction-hardened ground finishes well.
Can S30C be formed, bent or molded?
Hot forges readily at 1100–1200 °C; cold bending is limited — use generous radii or anneal first.
What is the maximum service temperature of S30C?
S30C 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 S30C-N and S30C-QT450?
N is the default condition — standard JIS reference condition: uniform fine-grain structure, balanced strength/toughness for general machine parts. QT450: for higher-strength small-section shafts, pins and studs; limited by the grade's low hardenability (thin sections only). Yield strength is 330 MPa in N versus 690 MPa in QT450.
How much does S30C cost?
S30C 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
- JIS G4051 Carbon steels for machine structural use — JSA (2016)
- SAE J403 / ASTM A29 grade 1030 — SAE / ASTM (2020)
- ASM Handbook Vol.1 — Properties and Selection: Irons, Steels — ASM International (1990)
- ASM Handbook Vol.16 — Machining — ASM International (1989)
- Mysteel / SMM (2025)
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.