Steel S30C-A (Solution annealed)
Temper
JIS S30C
Softest condition; pick for deep machining, cold forming or before subsequent heat treatment.
Values for the A condition
Other S30C tempers and conditions
S30C is listed in 7 conditions; see the grade overview at S30C.
Compare all 7 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
AThis page 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-A?
S30C-A is S30C in the A temper — softest condition; pick for deep machining, cold forming or before subsequent heat treatment. S30C-A has a yield strength of 280 MPa (40.6 ksi) and a tensile strength of 465 MPa (67.4 ksi) — weaker than 90% of steel grades. Elongation at break is 31% and the elastic modulus is 205 GPa (29.7 Msi). S30C-A 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). N is the default condition FabDigit quotes; A is available on request or by drawing note.
Advantages
- Ductile — tolerates forming and impact — 31%, better than 94% of steel grades
- 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
Limitations
- Low strength — 280 MPa (40.6 ksi), worse than 90% of steel grades
- Low fracture toughness — 65 MPa·√m (59.2 ksi·√in), worse than 75% of steel grades
S30C-A properties
Typical room-temperature values for S30C-A; 12 are specific to this condition. Other listed values are S30C reference data and may not represent this condition. Bars are the position among steel grades.
Physical3
S30C-A 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-A has a yield strength of 280 MPa (40.6 ksi) and a tensile strength of 465 MPa (67.4 ksi) — weaker than 90% of steel grades. Elongation at break is 31% and the elastic modulus is 205 GPa (29.7 Msi).
Thermal6
S30C-A 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-A 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-A 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-A's machinability is good (62/100, better than 89% of steel grades); weldability good (65/100); formability good (58/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with S30C-A
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.
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.
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 | — |
S30C-A — frequently asked
What is S30C-A used for?
S30C-A 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-A?
S30C-A has a typical yield strength of 280 MPa (40.6 ksi) and a tensile strength of 465 MPa (67.4 ksi) — weaker than 90% of steel grades. Strength varies by condition: see the 7 listed tempers.
Is S30C-A 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-A 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-A?
No inherent corrosion protection — apply phosphate + oil, black oxide, zinc plating or paint; takes hard chrome and induction-hardened ground finishes well.
Can S30C-A 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-A?
S30C-A 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.
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. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.