Steel SCM415
JIS SCM415
SCM415 is a chromium–molybdenum case-hardening steel to JIS G4105, roughly comparable to SAE 4118, designed to be carburized for a hard case over a tough core.
Values for the HR condition
SCM415 tempers and conditions
SCM415 is supplied in 7 conditions, soft to hard. HR 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 |
|---|---|---|---|---|---|---|
Temper | Softest condition — choose for heavy machining, cold heading or deep forming before carburizing. | 350 | 540 | 27 | 156 HB | — |
HRDefault Hot rolled | Standard as-rolled bar stock for machining and subsequent carburizing heat treatment. | 430 | 640 | 22 | 180 HB | 7.8 % IACS |
Heat Treat State | Uniform fine-grain structure before machining/carburizing; best machinability-to-distortion balance. | 440 | 630 | 23 | 180 HB | 7.8 % IACS |
Cold rolled | Cold-rolled strip/sheet for stamped and cold-formed parts that will be case hardened. | 570 | 700 | 14 | 205 HB | 7.8 % IACS |
Cold drawn | Cold-drawn bar with tight tolerance and bright surface for automatic-lathe parts and pins. | 600 | 720 | 13 | 215 HB | — |
Quenched and tempered | Through-hardened core condition per JIS G 4053 (≥830 MPa UTS) for shafts and fasteners not requiring a carburized case. | 700 | 880 | 18 | 26 HRC | — |
Carburized, quenched & tempered (case hardened) | The intended service condition: 58–62 HRC wear-resistant case over a tough ~30–40 HRC core for gears, cams and pins. | 780 | 1,000 | 12 | 60 HRC | — |
What is SCM415?
SCM415 is a chromium–molybdenum case-hardening steel to JIS G4105, roughly comparable to SAE 4118, designed to be carburized for a hard case over a tough core. It is widely used for automotive and industrial gears, shafts and pins, and is stocked hot-rolled, cold-rolled, cold-drawn, annealed, normalized, quenched-and-tempered and carburized. In the default condition it shows 430 MPa yield, 640 MPa tensile, 22 % elongation and 180 HB, with machinability about 58 % of AISI 1212. Core strength is modest next to 4140, corrosion resistance is nil, and carburizing distortion has to be corrected by grinding. SCM415 has a density of 7.85 g/cm³ (0.284 lb/in³), heavier than 56% of steel grades. It melts at 1,430°C (2,606 °F). SCM415 has a yield strength of 430 MPa (62.4 ksi) and a tensile strength of 640 MPa (92.8 ksi) — weaker than 51% of steel grades. Elongation at break is 22% and the elastic modulus is 206 GPa (29.9 Msi).
What is SCM415 used for?
- Gears
- Industrial drive shafts
- Pins
SCM415 properties
Typical room-temperature values for SCM415-HR; bars are the position among steel grades.
Physical3
SCM415 has a density of 7.85 g/cm³ (0.284 lb/in³), heavier than 56% of steel grades. It melts at 1,430°C (2,606 °F).
Mechanical16
SCM415 has a yield strength of 430 MPa (62.4 ksi) and a tensile strength of 640 MPa (92.8 ksi) — weaker than 51% of steel grades. Elongation at break is 22% and the elastic modulus is 206 GPa (29.9 Msi).
Thermal6
SCM415 is rated for continuous service to 400°C (752 °F). It conducts heat at 44 W/m·K (25.4 BTU/hr·ft·°F), better than 57% of steel grades. Thermal expansion is 12.3 µm/m·K (6.83 µin/in·°F).
Electrical3
SCM415 conducts electricity at 7.8 % IACS, worse than 57% of steel grades.
Chemical & Environmental3
Corrosion resistance is not recommended (12/100), worse than 53% of steel grades.
Sustainability4
Producing a kilogram of SCM415 takes about 27 MJ of energy and emits 2.1 kg of CO₂ — less than 59% of steel grades. Typical recycled content is 30%.
Manufacturability7
SCM415's machinability is good (58/100, better than 75% of steel grades); weldability good (55/100); formability good (60/100).
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. SCM415 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with SCM415
Is SCM415 easy to machine?
Machine in annealed or normalized state (≈60 % of AISI 1212); use carbide, moderate speeds and rigid setups, then grind after carburizing to correct heat-treat distortion.
Can SCM415 be welded?
Weldable before carburizing with low-hydrogen consumables and 150–250 °C preheat plus post-weld stress relief; welding a carburized case is not permitted.
Can SCM415 be formed, bent or molded?
Good cold heading and forging behaviour in the annealed/spheroidized condition; hot forge 1150–850 °C followed by normalizing.
Manufacturability
The process limits FabDigit applies to SCM415. Every SCM415 part is priced by an engineer; design inside these and the quote comes back without a redesign loop.
CNC machining
| Machinability | Better58 / 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 | Better60 / 100 |
|---|---|
| Weldability | Better55 / 100 |
SCM415 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 | 0.13 – 0.18 | 0.15 |
| Si | 0.15 – 0.35 | 0.25 |
| Mn | 0.6 – 0.85 | 0.72 |
| P | ≤ 0.03 | |
| S | ≤ 0.03 | |
| Niresidual, max | ≤ 0.25 | |
| Cr | 0.9 – 1.2 | 1.05 |
| Mo | 0.15 – 0.3 | 0.22 |
| Curesidual, max | ≤ 0.3 | |
| Fe | balance |
What surface finishes work on SCM415?
Not anodizable — protect with phosphating + oil, black oxide, zinc or Cr plating; carburized surfaces are usually ground/honed and shot-peened for fatigue life.
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 SCM415 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- JIS
- G 4053 SCM415
- Similar grades
- 4118
How much does SCM415 cost?
SCM415 is a standard-cost steel ($$), cheaper than about 71% 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.
SCM415 — frequently asked
What is SCM415 used for?
SCM415 is typically used for gears, industrial drive shafts and pins. In short: carburizing chrome-moly bar.
What is the yield strength of SCM415?
SCM415 has a typical yield strength of 430 MPa (62.4 ksi) and a tensile strength of 640 MPa (92.8 ksi) — weaker than 51% of steel grades. Strength varies by condition: see the 7 listed tempers.
Is SCM415 easy to machine?
Reasonably — machinability is rated good (58/100, better than 75% of steel grades). Machine in annealed or normalized state (≈60 % of AISI 1212); use carbide, moderate speeds and rigid setups, then grind after carburizing to correct heat-treat distortion.
Can SCM415 be welded?
Yes — weldability is rated good (55/100). Weldable before carburizing with low-hydrogen consumables and 150–250 °C preheat plus post-weld stress relief; welding a carburized case is not permitted.
What surface finishes work on SCM415?
Not anodizable — protect with phosphating + oil, black oxide, zinc or Cr plating; carburized surfaces are usually ground/honed and shot-peened for fatigue life.
Can SCM415 be formed, bent or molded?
Good cold heading and forging behaviour in the annealed/spheroidized condition; hot forge 1150–850 °C followed by normalizing.
What is the maximum service temperature of SCM415?
SCM415 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 SCM415-HR and SCM415-CD?
HR is the default condition — standard as-rolled bar stock for machining and subsequent carburizing heat treatment. CD: cold-drawn bar with tight tolerance and bright surface for automatic-lathe parts and pins. Yield strength is 430 MPa in HR versus 600 MPa in CD.
How much does SCM415 cost?
SCM415 is a standard-cost steel ($$), cheaper than about 71% 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 SCM415?
Yes — SCM415 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 4053 — Low-alloyed steels for machine structural use — JSA (2016)
- ASM Handbook Vol.1 — Properties and Selection: Irons, Steels and High-Performance Alloys — ASM International (1990)
- ASM Handbook Vol.4 — Heat Treating (carburizing of Cr-Mo steels) — 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.