Steel CP800-HR (Hot rolled)
Supply condition
Hot-rolled CP800 in thicker gauges (2–8 mm) for chassis, wheels and suspension arms where stretch-flange (hole expansion) capability dominates.
Values for the HR condition
Other CP800 tempers and conditions
CP800 is listed in 2 conditions; see the grade overview at CP800.
- CR
- HR
Compare all 2 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
CRDefault Cold rolled | Standard uncoated cold-rolled CP800 coil/blank for stamped and roll-formed structural parts that will be painted or e-coated. | 620 | 840 | 13 | 25 HRC | 7.8 % IACS |
HRThis page Hot rolled | Hot-rolled CP800 in thicker gauges (2–8 mm) for chassis, wheels and suspension arms where stretch-flange (hole expansion) capability dominates. | 660 | 830 | 14 | 24 HRC | 8 % IACS |
What is CP800-HR?
CP800-HR is CP800 supplied in the HR condition — hot-rolled CP800 in thicker gauges (2–8 mm) for chassis, wheels and suspension arms where stretch-flange (hole expansion) capability dominates. CP800-HR has a yield strength of 660 MPa (95.7 ksi) and a tensile strength of 830 MPa (120 ksi) — stronger than 80% of steel grades. Elongation at break is 14% and the elastic modulus is 210 GPa (30.5 Msi). CP800-HR has a density of 7.85 g/cm³ (0.284 lb/in³), heavier than 56% of steel grades. It melts at 1,460°C (2,660 °F). CR is the default condition FabDigit quotes; HR is available on request or by drawing note.
Advantages
- High strength — 660 MPa (95.7 ksi), better than 80% of steel grades
Limitations
- Limited service temperature — 250°C (482 °F), worse than 85% of steel grades
- Hard to polish — 45/100, worse than 84% of steel grades
- Difficult to machine — 37/100, worse than 81% of steel grades
- Low fracture toughness — 60 MPa·√m (54.6 ksi·√in), worse than 78% of steel grades
- Limited ductility — 14%, worse than 75% of steel grades
CP800-HR properties
Typical room-temperature values for CP800-HR; 23 are specific to this condition. Other listed values are CP800 reference data and may not represent this condition. Bars are the position among steel grades.
Physical3
CP800-HR has a density of 7.85 g/cm³ (0.284 lb/in³), heavier than 56% of steel grades. It melts at 1,460°C (2,660 °F).
Mechanical17
CP800-HR has a yield strength of 660 MPa (95.7 ksi) and a tensile strength of 830 MPa (120 ksi) — stronger than 80% of steel grades. Elongation at break is 14% and the elastic modulus is 210 GPa (30.5 Msi).
Thermal6
CP800-HR is rated for continuous service to 250°C (482 °F). It conducts heat at 40 W/m·K (23.1 BTU/hr·ft·°F), worse than 64% of steel grades. Thermal expansion is 12 µm/m·K (6.67 µin/in·°F).
Electrical3
CP800-HR conducts electricity at 8 % IACS, better than 55% of steel grades.
Chemical & Environmental3
Corrosion resistance is not recommended (10/100), worse than 86% of steel grades.
Sustainability4
Producing a kilogram of CP800-HR takes about 28 MJ of energy and emits 2.2 kg of CO₂ — less than 56% of steel grades. Typical recycled content is 20%.
Manufacturability7
CP800-HR's machinability is fair (37/100, worse than 81% of steel grades); weldability very good (70/100); formability fair (50/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with CP800-HR
Is CP800 easy to machine?
Machine only for trimming/piercing: use carbide or PVD-coated punches, generous clearance and rigid setups; high work-hardening makes drilling and tapping slow.
Can CP800 be welded?
Good resistance spot weldability with low CEV; use adaptive/pulsed schedules and post-weld temper pulses, and low-hydrogen practice for GMAW to avoid HAZ softening and cold cracking.
Can CP800 be formed, bent or molded?
Excellent stretch-flanging and hole expansion but limited total elongation — design for large springback compensation, high press tonnage and wear-resistant tool coatings.
What surface finishes work on CP800?
Not anodizable; supply as GI/GA/EG zinc-coated or phosphate + cathodic e-coat; avoid electroplating processes with hydrogen embrittlement risk on high-strength gauges.
CP800 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 |
|---|---|---|
| CEN 10338 HCT780C max | ≤ 0.18 | 0.12 |
| Si | ≤ 0.8 | 0.4 |
| Mn | ≤ 2.2 | 1.9 |
| P | ≤ 0.08 | 0.02 |
| S | ≤ 0.02 | 0 |
| Altotal Al | 0.02 – 2 | 0.04 |
| Cr+Mohardenability / bainite stabilisers | ≤ 1 | 0.35 |
| Nb+Timicroalloy precipitation strengthening | ≤ 0.15 | 0.06 |
| V | ≤ 0.2 | 0.01 |
| B | ≤ 0.01 | 0 |
| Fe | balance | — |
CP800-HR — frequently asked
What is CP800-HR used for?
CP800-HR is typically used for automotive bumper beams, B-pillar reinforcements, side-impact door beams, seat frame structures, roll-formed chassis and sill members and wheel discs and rims. In short: complex-phase auto sheet.
What is the yield strength of CP800-HR?
CP800-HR has a typical yield strength of 660 MPa (95.7 ksi) and a tensile strength of 830 MPa (120 ksi) — stronger than 80% of steel grades. Strength varies by condition: see the 2 listed tempers.
Is CP800-HR easy to machine?
Not especially — machinability is rated fair (37/100, worse than 81% of steel grades). Machine only for trimming/piercing: use carbide or PVD-coated punches, generous clearance and rigid setups; high work-hardening makes drilling and tapping slow.
Can CP800-HR be welded?
Yes — weldability is rated very good (70/100). Good resistance spot weldability with low CEV; use adaptive/pulsed schedules and post-weld temper pulses, and low-hydrogen practice for GMAW to avoid HAZ softening and cold cracking.
What surface finishes work on CP800-HR?
Not anodizable; supply as GI/GA/EG zinc-coated or phosphate + cathodic e-coat; avoid electroplating processes with hydrogen embrittlement risk on high-strength gauges.
Can CP800-HR be formed, bent or molded?
Excellent stretch-flanging and hole expansion but limited total elongation — design for large springback compensation, high press tonnage and wear-resistant tool coatings.
What is the maximum service temperature of CP800-HR?
CP800-HR is rated for continuous use to about 250°C (482 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between CP800-CR and CP800-HR?
CR is the default condition — standard uncoated cold-rolled CP800 coil/blank for stamped and roll-formed structural parts that will be painted or e-coated. HR: hot-rolled CP800 in thicker gauges (2–8 mm) for chassis, wheels and suspension arms where stretch-flange (hole expansion) capability dominates. Yield strength is 620 MPa in CR versus 660 MPa in HR.
Can FabDigit make parts in CP800-HR?
Yes — CP800-HR is available for 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
- EN 10338 — Hot rolled and cold rolled uncoated multiphase steel products for cold forming — CEN (2015)
- VDA 239-100 — Sheet Steel for Cold Forming — VDA (2016)
- Advanced High-Strength Steels Application Guidelines V7 — WorldAutoSteel (2021)
- Complex phase steel CP-W / CP-K product information — thyssenkrupp Steel Europe (2022)
- Complex Phase steels for automotive body and chassis — ArcelorMittal (2023)
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.