Steel SCM415 · heat-treated state
Steel SCM415 Q&T
Properties of the Q&T condition, compared with the other SCM415 tempers.
Through-hardened core condition per JIS G 4053 (≥830 MPa UTS) for shafts and fasteners not requiring a carburized case.
What is SCM415 Q&T?
SCM415 Q&T is SCM415 heat treated to Q&T — through-hardened core condition per JIS G 4053 (≥830 MPa UTS) for shafts and fasteners not requiring a carburized case. SCM415 Q&T has a yield strength of 700 MPa (102 ksi) and a tensile strength of 880 MPa (128 ksi) — stronger than 81% of steel grades. Elongation at break is 18% and the elastic modulus is 206 GPa (29.9 Msi). SCM415 Q&T 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). HR is the default condition FabDigit quotes; Q&T is available on request or by drawing note.
Advantages
- High strength — 700 MPa (102 ksi), better than 81% of steel grades
SCM415 Q&T properties
Typical room-temperature values for SCM415 Q&T — 14 properties are specific to this condition; the rest are grade-level values shared by every SCM415 temper. Each bar shows where the value sits among the steel grades in FabDigit's library — further right is higher.
Physical3
SCM415 Q&T 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).
Mechanical14
SCM415 Q&T has a yield strength of 700 MPa (102 ksi) and a tensile strength of 880 MPa (128 ksi) — stronger than 81% of steel grades. Elongation at break is 18% and the elastic modulus is 206 GPa (29.9 Msi).
Thermal6
SCM415 Q&T 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 Q&T conducts electricity at 7.8 % IACS, worse than 58% of steel grades.
Chemical & Environmental3
Corrosion resistance is not recommended (12/100), worse than 53% of steel grades.
Sustainability4
Producing a kilogram of SCM415 Q&T 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 Q&T's machinability is fair (45/100, worse than 65% of steel grades); weldability fair (40/100); formability good (60/100).
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
Other SCM415 tempers and conditions
SCM415 is also supplied in 6 other conditions. The full side-by-side table is on the SCM415 overview.
- HRDefaultStandard as-rolled bar stock for machining and subsequent carburizing heat treatment.430 MPa yield · 180 HB
- CarburizedThe intended service condition: 58–62 HRC wear-resistant case over a tough ~30–40 HRC core for gears, cams and pins.780 MPa yield · 60 HRC
- Q&TThrough-hardened core condition per JIS G 4053 (≥830 MPa UTS) for shafts and fasteners not requiring a carburized case.700 MPa yield · 26 HRC
- CDCold-drawn bar with tight tolerance and bright surface for automatic-lathe parts and pins.600 MPa yield · 215 HB
- NormalizedUniform fine-grain structure before machining/carburizing; best machinability-to-distortion balance.440 MPa yield · 180 HB
- AnnealedSoftest condition — choose for heavy machining, cold heading or deep forming before carburizing.350 MPa yield · 156 HB
Working with SCM415 Q&T
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.
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.
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 | — |
SCM415 Q&T — frequently asked
What is SCM415 Q&T used for?
SCM415 Q&T is typically used for gears, industrial drive shafts and pins. In short: carburizing chrome-moly bar.
What is the yield strength of SCM415 Q&T?
SCM415 Q&T has a typical yield strength of 700 MPa (102 ksi) and a tensile strength of 880 MPa (128 ksi) — stronger than 81% of steel grades. Strength varies by condition: see the 7 listed tempers.
Is SCM415 Q&T easy to machine?
Reasonably — machinability is rated fair (45/100, worse than 65% 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 Q&T be welded?
With care — weldability is rated fair (40/100). 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 Q&T?
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 Q&T 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 Q&T?
SCM415 Q&T 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.
Can FabDigit make parts in SCM415 Q&T?
Yes — SCM415 Q&T is available for CNC machining and sheet metal with instant online pricing. 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. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.