Steel S50C
JIS S50C
S50C is the JIS G4051 medium-carbon structural steel with about 0.50 % carbon, equivalent to AISI 1050 and DIN C50.
Values for the Normalized condition
S50C tempers and conditions
S50C is supplied in 9 conditions, soft to hard. Normalized is the default FabDigit quotes; the values on this page are for it.
Compare all 9 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
full/spheroidize annealed (soft) | Pick when maximum machinability, cold formability or easiest drilling is needed before hardening. | 365 | 636 | 24 | 187 HB | — |
Hot rolled | Cheapest stock form for weld fabrications and parts that will be machined then heat treated. | 380 | 690 | 17 | 197 HB | — |
Pre-hardened mold plate | Standard S50C mold-base plate condition: stress-relieved, machined flat, used directly without further heat treatment. | 420 | 700 | 20 | 14 HRC | 10 % IACS |
NormalizedDefault air cooled from ~870–900 °C | Default stocked condition: uniform fine pearlitic structure, balanced strength and machinability for general shafting and mold plate. | 427 | 748 | 20 | 217 HB | — |
Induction/flame hardened case | Use for shaft journals, guide rails and sprocket teeth needing a hard wear surface over a tough normalized core. | 430 | 750 | 18 | 55 HRC | 9 % IACS |
Cold drawn | Choose for close-tolerance, bright bar used as-supplied for shafts, pins and studs with higher yield strength. | 580 | 690 | 10 | 197 HB | — |
Quenched and tempered | General-purpose quench-and-temper level for shafts and gear blanks needing toughness with moderate strength. | 700 | 950 | 17 | 30 HRC | — |
Quenched and tempered | Higher-strength Q&T level for wear-loaded pins, cams and small shafts where impact demand is moderate. | 850 | 1,100 | 14 | 36 HRC | — |
Quenched and low tempered | Maximum through-hardness practical for S50C in small sections where wear resistance dominates over toughness. | 1,050 | 1,330 | 10 | 43 HRC | — |
What is S50C?
S50C is the JIS G4051 medium-carbon structural steel with about 0.50 % carbon, equivalent to AISI 1050 and DIN C50. It is used for mould base plates, shafts, gears, connecting rods and pins because it gives moderate strength cheaply and responds well to quench-and-temper and induction hardening (52–58 HRC on file). Normalized bar runs 427 MPa yield, 748 MPa tensile, 20 % elongation and 217 HB. Limits are low hardenability in thick sections, no bare corrosion resistance, and a carbon equivalent near 0.6 that demands preheat and post-heat when welding; 4140 is the step up for large hardened parts. S50C 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). S50C has a yield strength of 427 MPa (61.9 ksi) and a tensile strength of 748 MPa (108 ksi) — weaker than 52% of steel grades. Elongation at break is 20% and the elastic modulus is 205 GPa (29.7 Msi).
What is S50C used for?
- Crankshafts
- Shafts
- Industrial bolts
Advantages
- Conducts heat well — 49 W/m·K (28.3 BTU/hr·ft·°F), better than 83% of steel grades
- High electrical conductivity — 10 % IACS, better than 83% of steel grades
Limitations
- Low fracture toughness — 50 MPa·√m (45.5 ksi·√in), worse than 86% of steel grades
S50C properties
Typical room-temperature values for S50C-Normalized; bars are the position among steel grades.
Physical3
S50C 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
S50C has a yield strength of 427 MPa (61.9 ksi) and a tensile strength of 748 MPa (108 ksi) — weaker than 52% of steel grades. Elongation at break is 20% and the elastic modulus is 205 GPa (29.7 Msi).
Thermal6
S50C is rated for continuous service to 350°C (662 °F). It conducts heat at 49 W/m·K (28.3 BTU/hr·ft·°F), better than 83% of steel grades. Thermal expansion is 11.7 µm/m·K (6.5 µin/in·°F).
Electrical3
S50C conducts electricity at 10 % IACS, better than 83% of steel grades.
Chemical & Environmental3
Corrosion resistance is not recommended (12/100), worse than 53% of steel grades.
Sustainability4
Producing a kilogram of S50C takes about 25 MJ of energy and emits 2 kg of CO₂ — less than 82% of steel grades. Typical recycled content is 25%.
Manufacturability7
S50C's machinability is fair (50/100, worse than 53% of steel grades); weldability fair (35/100); formability fair (35/100).
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. S50C is highlighted; hover a dot for its name, or open the interactive family chart.
Working with S50C
Is S50C easy to machine?
Machines predictably at ~50% of 1212; best in annealed or normalized state with carbide tooling, 120–200 m/min turning, ample coolant to avoid built-up edge.
Can S50C be welded?
CE ≈ 0.6 — preheat 200–300 °C, use low-hydrogen E7018/ER70S electrodes and post-weld stress relief or temper to avoid HAZ cracking.
Can S50C be formed, bent or molded?
Hot forge 1100–1200 °C with slow cooling; cold bending is limited — use generous radii (≥3t) in the annealed condition only.
Manufacturability
The process limits FabDigit applies to S50C. Every S50C part is priced by an engineer; design inside these and the quote comes back without a redesign loop.
CNC machining
| Machinability | Better50 / 100 |
|---|---|
| ISO material group | P.2 |
| Cutting speed (rough / finish) | 180 / 210 m/min |
| Minimum wall | 0.8 mm |
| Minimum internal radius | 1 mm |
| Drill depth limit | 5× diameter |
| Best surface (machined / polished) | Ra 1.6 / — |
| Hardenable after machining | No |
Sheet metal
| Formability | Better35 / 100 |
|---|---|
| Weldability | Better35 / 100 |
S50C 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 | 0.47 – 0.53 | 0.5 |
| Si | 0.15 – 0.35 | 0.25 |
| Mn | 0.6 – 0.9 | 0.75 |
| P | ≤ 0.03 | 0.02 |
| S | ≤ 0.04 | 0.02 |
| Curesidual, max | ≤ 0.3 | 0.1 |
| Niresidual, max | ≤ 0.2 | 0.05 |
| Crresidual; Ni+Cr ≤ 0.35 | ≤ 0.2 | 0.05 |
| Fe | balance |
What surface finishes work on S50C?
No corrosion resistance bare — protect with black oxide, phosphate, zinc/hard-chrome plating, nitriding or paint; polishes to a fair mold-plate finish but carbide inclusions limit mirror work.
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).
Plating
CVD Coating
Black / Phosphate
Thermal Spray
Equivalent designations
Standards and trade names that resolve to Steel S50C in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
How much does S50C cost?
S50C 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.
S50C — frequently asked
What is S50C used for?
S50C is typically used for crankshafts, shafts and industrial bolts. In short: workhorse Japanese carbon bar.
What is the yield strength of S50C?
S50C has a typical yield strength of 427 MPa (61.9 ksi) and a tensile strength of 748 MPa (108 ksi) — weaker than 52% of steel grades. Strength varies by condition: see the 9 listed tempers.
Is S50C easy to machine?
Reasonably — machinability is rated fair (50/100, worse than 53% of steel grades). Machines predictably at ~50% of 1212; best in annealed or normalized state with carbide tooling, 120–200 m/min turning, ample coolant to avoid built-up edge.
Can S50C be welded?
With care — weldability is rated fair (35/100). CE ≈ 0.6 — preheat 200–300 °C, use low-hydrogen E7018/ER70S electrodes and post-weld stress relief or temper to avoid HAZ cracking.
What surface finishes work on S50C?
No corrosion resistance bare — protect with black oxide, phosphate, zinc/hard-chrome plating, nitriding or paint; polishes to a fair mold-plate finish but carbide inclusions limit mirror work.
Can S50C be formed, bent or molded?
Hot forge 1100–1200 °C with slow cooling; cold bending is limited — use generous radii (≥3t) in the annealed condition only.
What is the maximum service temperature of S50C?
S50C 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 S50C Normalized and S50C-CD?
Normalized is the default condition — default stocked condition: uniform fine pearlitic structure, balanced strength and machinability for general shafting and mold plate. CD: choose for close-tolerance, bright bar used as-supplied for shafts, pins and studs with higher yield strength. Yield strength is 427 MPa in Normalized versus 580 MPa in CD.
How much does S50C cost?
S50C 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.
Can FabDigit make parts in S50C?
Yes — S50C 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
- JIS G 4051 — Carbon steels for machine structural use — JSA (2016)
- GB/T 699 — Quality carbon structural steels (50 ) — SAC (2015)
- ASM Handbook Vol.1 — Properties and Selection: Irons, Steels (AISI 1050) — ASM International (1990)
- ASM Handbook Vol.19 — Fatigue and Fracture — ASM International (1996)
- ASTM A29/A29M — Steel bars, carbon and alloy, hot-wrought — ASTM (2020)
- Mold base plate (S50C) product data — LKM / FUTABA mold base catalogs (2022)
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.