Steel SCr415-HR (Hot rolled)
Supply condition
JIS SCr415
Cheapest mill condition for bar that will be forged or fully heat treated afterwards.
Values for the HR condition
Other SCr415 tempers and conditions
SCr415 is listed in 8 conditions; see the grade overview at SCr415.
Compare all 8 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Spheroidize annealed | Choose for cold-headed or cold-extruded gear and fastener blanks needing maximum ductility. | 300 | 480 | 31 | 140 HB | 8 % IACS |
ADefault Solution annealed | Standard stocked condition: soft and dimensionally stable for machining gear blanks before carburizing. | 340 | 540 | 26 | 160 HB | — |
HRThis page Hot rolled | Cheapest mill condition for bar that will be forged or fully heat treated afterwards. | 400 | 600 | 21 | 180 HB | — |
Normalized | Used to refine forging structure and give uniform grain size before carburizing. | 420 | 620 | 23 | 180 HB | 7.8 % IACS |
Carbonitrided and tempered | Use for small, low-load gears, washers and levers where a 0.1–0.4 mm hard, wear-resistant case is enough. | 520 | 750 | 18 | 59 HRC | 7.5 % IACS |
Cold drawn | Pick for close-tolerance bright bar for pins, shafts and small gear blanks with minimal turning. | 580 | 710 | 12 | 210 HB | — |
Carburized, quenched and tempered | The service condition for gears and splines: 0.6–1.2 mm effective case at 58–62 HRC over a tough core. | 640 | 900 | 17 | 60 HRC | — |
Quenched and tempered | For small, thin parts that need a hard through-section rather than a carburized case. | 760 | 1,000 | 13 | 32 HRC | — |
What is SCr415-HR?
SCr415-HR is SCr415 supplied in the HR condition — cheapest mill condition for bar that will be forged or fully heat treated afterwards. SCr415-HR has a yield strength of 400 MPa (58 ksi) and a tensile strength of 600 MPa (87 ksi) — weaker than 60% of steel grades. Elongation at break is 21% and the elastic modulus is 206 GPa (29.9 Msi). SCr415-HR 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). A is the default condition FabDigit quotes; HR is available on request or by drawing note.
SCr415-HR properties
Typical room-temperature values for SCr415-HR; 10 are specific to this condition. Other listed values are SCr415 reference data and may not represent this condition. Bars are the position among steel grades.
Physical3
SCr415-HR 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).
Mechanical15
SCr415-HR has a yield strength of 400 MPa (58 ksi) and a tensile strength of 600 MPa (87 ksi) — weaker than 60% of steel grades. Elongation at break is 21% and the elastic modulus is 206 GPa (29.9 Msi).
Thermal6
SCr415-HR is rated for continuous service to 350°C (662 °F). It conducts heat at 44 W/m·K (25.4 BTU/hr·ft·°F), better than 57% of steel grades. Thermal expansion is 11.9 µm/m·K (6.61 µin/in·°F).
Electrical3
SCr415-HR 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 SCr415-HR takes about 27 MJ of energy and emits 2 kg of CO₂ — less than 59% of steel grades. Typical recycled content is 30%.
Manufacturability7
SCr415-HR's machinability is good (55/100, better than 62% of steel grades); weldability good (60/100); formability fair (50/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with SCr415-HR
Is SCr415 easy to machine?
Machine soft (annealed 143–187 HB) with carbide or HSS at ~65 % of 1212 rates; leave 0.1–0.3 mm stock for post-carburizing grinding since the 60 HRC case needs CBN/grinding.
Can SCr415 be welded?
Weldable in the soft condition with low-hydrogen consumables, 150–250 °C preheat and post-weld stress relief; do not weld carburized surfaces (cracking and case softening).
Can SCr415 be formed, bent or molded?
Good hot forgeability at 1100–1200 °C; cold heading and extrusion practical after spheroidize annealing plus phosphate/soap lubrication; normalize before carburizing to control distortion.
What surface finishes work on SCr415?
No anodizing (ferrous) — protect with oil, manganese phosphate, black oxide, or zinc/nickel plating (bake to avoid hydrogen embrittlement of the hardened case); ground and shot-peened gear flanks give best fatigue life.
SCr415 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 – 0.9 | 0.75 |
| P | ≤ 0.03 | — |
| S | ≤ 0.03 | — |
| Cr | 0.9 – 1.2 | 1.05 |
| Niresidual, max | ≤ 0.25 | — |
| Curesidual, max | ≤ 0.3 | — |
| Fe | balance | — |
SCr415-HR — frequently asked
What is SCr415-HR used for?
SCr415-HR is typically used for carburized gears, shafts and pins. In short: entry-level carburizing chrome steel; good soft-state machinability; 5115 / 15Cr equivalent.
What is the yield strength of SCr415-HR?
SCr415-HR has a typical yield strength of 400 MPa (58 ksi) and a tensile strength of 600 MPa (87 ksi) — weaker than 60% of steel grades. Strength varies by condition: see the 8 listed tempers.
Is SCr415-HR easy to machine?
Reasonably — machinability is rated good (55/100, better than 62% of steel grades). Machine soft (annealed 143–187 HB) with carbide or HSS at ~65 % of 1212 rates; leave 0.1–0.3 mm stock for post-carburizing grinding since the 60 HRC case needs CBN/grinding.
Can SCr415-HR be welded?
Yes — weldability is rated good (60/100). Weldable in the soft condition with low-hydrogen consumables, 150–250 °C preheat and post-weld stress relief; do not weld carburized surfaces (cracking and case softening).
What surface finishes work on SCr415-HR?
No anodizing (ferrous) — protect with oil, manganese phosphate, black oxide, or zinc/nickel plating (bake to avoid hydrogen embrittlement of the hardened case); ground and shot-peened gear flanks give best fatigue life.
Can SCr415-HR be formed, bent or molded?
Good hot forgeability at 1100–1200 °C; cold heading and extrusion practical after spheroidize annealing plus phosphate/soap lubrication; normalize before carburizing to control distortion.
What is the maximum service temperature of SCr415-HR?
SCr415-HR 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 SCr415-A and SCr415-QT?
A is the default condition — standard stocked condition: soft and dimensionally stable for machining gear blanks before carburizing. QT: for small, thin parts that need a hard through-section rather than a carburized case. Yield strength is 340 MPa in A versus 760 MPa in QT.
Sources
- JIS G 4053 — Low-alloyed steels for machine structural use — JISC (2016)
- GB/T 3077 — Alloy structural steels (15Cr) — SAC (2015)
- SAE J404 / ASTM A29 (5115 chemical limits) — SAE / ASTM (2020)
- ASM Handbook Vol.1 — Properties and Selection: Irons, Steels, and High-Performance Alloys — ASM International (1990)
- ASM Handbook Vol.4A — Steel Heat Treating Fundamentals and Processes (carburizing) — ASM International (2013)
- ASM Handbook Vol.16 — Machining — ASM International (1989)
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.