Steel 4815-CR (Cold rolled)
Supply condition
AISI/SAE 4815 · UNS G48150
Sheet/strip form for stamped and formed parts that will later be carburized; limited availability in this grade.
Values for the CR condition
Other 4815 tempers and conditions
4815 is listed in 7 conditions; see the grade overview at 4815.
Compare all 7 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
full/subcritical anneal, softest machining condition | Pick for maximum machinability and cold-forming ability before case hardening. | 415 | 640 | 27 | 187 HB | 8 % IACS |
HRDefault Hot rolled | Standard mill stock condition for bar and billet intended for machining and subsequent carburizing. | 420 | 690 | 22 | 200 HB | 7.8 % IACS |
austenitize ≈ 900 °C, air cool | Use to homogenize structure and refine grain in forgings before carburizing or final machining. | 455 | 730 | 24 | 212 HB | 7.8 % IACS |
CRThis page Cold rolled | Sheet/strip form for stamped and formed parts that will later be carburized; limited availability in this grade. | 600 | 740 | 16 | 217 HB | 7.8 % IACS |
Cold drawn | Choose for tighter size tolerance, better surface and higher as-supplied strength on small-diameter bar. | 655 | 760 | 15 | 223 HB | 7.8 % IACS |
Quenched and tempered | Direct-quench-and-temper condition used where a tough, moderately strong through-hardened core is required without a carburized case. | 780 | 1,000 | 16 | 31 HRC | — |
case 58–63 HRC, tempered ≈ 150–180 °C | The intended service condition: hard wear- and pitting-resistant case on a tough Ni-Mo core for gears, pinions and bearing races. | 800 | 1,050 | 13 | 61 HRC | 7.2 % IACS |
What is 4815-CR?
4815-CR is 4815 supplied in the CR condition — sheet/strip form for stamped and formed parts that will later be carburized; limited availability in this grade. 4815-CR has a yield strength of 600 MPa (87 ksi) and a tensile strength of 740 MPa (107 ksi) — stronger than 77% of steel grades. Elongation at break is 16% and the elastic modulus is 205 GPa (29.7 Msi). 4815-CR has a density of 7.87 g/cm³ (0.284 lb/in³), heavier than 92% of steel grades. It melts at 1,425°C (2,597 °F). HR is the default condition FabDigit quotes; CR is available on request or by drawing note.
Advantages
- High strength — 600 MPa (87 ksi), better than 77% of steel grades
Limitations
- Poor heat conductor — 35 W/m·K (20.2 BTU/hr·ft·°F), worse than 75% of steel grades
4815-CR properties
Typical room-temperature values for 4815-CR; 22 are specific to this condition. Other listed values are 4815 reference data and may not represent this condition. Bars are the position among steel grades.
Physical3
4815-CR has a density of 7.87 g/cm³ (0.284 lb/in³), heavier than 92% of steel grades. It melts at 1,425°C (2,597 °F).
Mechanical16
4815-CR has a yield strength of 600 MPa (87 ksi) and a tensile strength of 740 MPa (107 ksi) — stronger than 77% of steel grades. Elongation at break is 16% and the elastic modulus is 205 GPa (29.7 Msi).
Thermal6
4815-CR is rated for continuous service to 350°C (662 °F). It conducts heat at 35 W/m·K (20.2 BTU/hr·ft·°F), worse than 75% of steel grades. Thermal expansion is 12.2 µm/m·K (6.78 µin/in·°F).
Electrical3
4815-CR conducts electricity at 7.8 % IACS, worse than 57% of steel grades.
Chemical & Environmental2
Corrosion resistance is not recommended (12/100), worse than 53% of steel grades.
Sustainability4
Producing a kilogram of 4815-CR takes about 32 MJ of energy and emits 2.4 kg of CO₂ — more than 70% of steel grades. Typical recycled content is 30%.
Manufacturability7
4815-CR's machinability is good (55/100, better than 62% of steel grades); weldability fair (50/100); formability fair (45/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with 4815-CR
Is 4815 easy to machine?
Machines like a tough 200 HB alloy steel — gummy in the annealed state; use sharp positive-rake carbide, generous feed and coolant, and finish-machine before carburizing since the case is nearly unmachinable.
Can 4815 be welded?
Weldable at 0.15 % C but the 3.5 % Ni raises hardenability: preheat 150–250 °C, use low-hydrogen or Ni-bearing filler and post-weld stress relief; avoid welding carburized surfaces.
Can 4815 be formed, bent or molded?
Cold forms and cold heads reasonably in the annealed condition; hot work 1100–1200 °C and normalize afterwards to break up the coarse as-forged grain.
What surface finishes work on 4815?
No inherent corrosion resistance — protect with oil, black oxide, manganese phosphate, zinc or chrome plating; grind/hone after carburizing for gear-quality surface finish.
4815 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 |
|---|---|---|
| Ccarburizing carbon level | 0.13 – 0.18 | 0.16 |
| Mn | 0.4 – 0.6 | 0.5 |
| Si | 0.15 – 0.35 | 0.25 |
| Nicore toughness and hardenability | 3.25 – 3.75 | 3.5 |
| Mo | 0.2 – 0.3 | 0.25 |
| P | ≤ 0.04 | — |
| Smax (0.15–0.35 for resulfurized 4815H variants not standard) | ≤ 0.04 | — |
| Fe | balance | — |
4815-CR — frequently asked
What is 4815-CR used for?
4815-CR is typically used for gears, pins and camshafts. In short: carburizing nickel-moly bar.
What is the yield strength of 4815-CR?
4815-CR has a typical yield strength of 600 MPa (87 ksi) and a tensile strength of 740 MPa (107 ksi) — stronger than 77% of steel grades. Strength varies by condition: see the 7 listed tempers.
Is 4815-CR easy to machine?
Reasonably — machinability is rated good (55/100, better than 62% of steel grades). Machines like a tough 200 HB alloy steel — gummy in the annealed state; use sharp positive-rake carbide, generous feed and coolant, and finish-machine before carburizing since the case is nearly unmachinable.
Can 4815-CR be welded?
With care — weldability is rated fair (50/100). Weldable at 0.15 % C but the 3.5 % Ni raises hardenability: preheat 150–250 °C, use low-hydrogen or Ni-bearing filler and post-weld stress relief; avoid welding carburized surfaces.
What surface finishes work on 4815-CR?
No inherent corrosion resistance — protect with oil, black oxide, manganese phosphate, zinc or chrome plating; grind/hone after carburizing for gear-quality surface finish.
Can 4815-CR be formed, bent or molded?
Cold forms and cold heads reasonably in the annealed condition; hot work 1100–1200 °C and normalize afterwards to break up the coarse as-forged grain.
What is the maximum service temperature of 4815-CR?
4815-CR 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 4815-HR and 4815-CD?
HR is the default condition — standard mill stock condition for bar and billet intended for machining and subsequent carburizing. CD: choose for tighter size tolerance, better surface and higher as-supplied strength on small-diameter bar. Yield strength is 420 MPa in HR versus 655 MPa in CD.
Can FabDigit make parts in 4815-CR?
Yes — 4815-CR 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
- SAE J404 — Chemical Compositions of SAE Alloy Steels — SAE International (2021)
- ASTM A29/A29M — Steel Bars, Carbon and Alloy, Hot-Wrought, General Requirements — ASTM (2020)
- ASTM A322 — Steel Bars, Alloy, Standard Grades — ASTM (2020)
- ASM Handbook Vol.1 — Properties and Selection: Irons, Steels, and High-Performance Alloys — ASM International (1990)
- ASM Handbook Vol.4 — Heat Treating (carburizing steels) — ASM International (1991)
- ASM Handbook Vol.16 — Machining (machinability ratings) — 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.