Steel CP800
CP800 is a complex-phase advanced high-strength steel of the 800 MPa tensile class, with a fine-grained ferrite/bainite matrix plus limited martensite and precipitation strengthening (620 MPa yield, 840 MPa tensile, 13% elongation, about 250 HB).
Values for the CR condition
CP800 tempers and conditions
CP800 is supplied in 2 conditions, soft to hard. CR is the default FabDigit quotes; the values on this page are for it.
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 |
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 |
Supply forms, finishes and certifications
Ways CP800 is supplied — form, process route, surface or paperwork — without a datasheet of their own. The property values above apply.
| Option | What it is | Type |
|---|---|---|
EG | Electrogalvanized | Coating |
GA | Galvannealed | Coating |
GI | Hot-dip galvanized | Coating |
What is CP800?
CP800 is a complex-phase advanced high-strength steel of the 800 MPa tensile class, with a fine-grained ferrite/bainite matrix plus limited martensite and precipitation strengthening (620 MPa yield, 840 MPa tensile, 13% elongation, about 250 HB). Engineers select it for its high yield ratio and better hole expansion and local formability than DP steel of the same strength class; it is stocked as cold-rolled and hot-rolled sheet and as zinc-coated coil (GI, GA, EG). Total elongation is lower than DP/TRIP grades, springback and die wear are high, and bare sheet corrodes like plain carbon steel, so zinc coating or paint is required. DP800 is the alternative when stretch-draw elongation matters more than flangeability. CP800 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). CP800 has a yield strength of 620 MPa (89.9 ksi) and a tensile strength of 840 MPa (122 ksi) — stronger than 78% of steel grades. Elongation at break is 13% and the elastic modulus is 210 GPa (30.5 Msi).
What is CP800 used for?
- Automotive bumper beams
- B-pillar reinforcements
- Side-impact door beams
- Seat frame structures
- Roll-formed chassis and sill members
- Wheel discs and rims
- Crash boxes and crush cans
Advantages
- High strength — 620 MPa (89.9 ksi), better than 78% of steel grades
Limitations
- Limited service temperature — 200°C (392 °F), worse than 93% of steel grades
- Difficult to machine — 35/100, worse than 84% of steel grades
- Hard to polish — 45/100, worse than 84% of steel grades
- Low fracture toughness — 55 MPa·√m (50.1 ksi·√in), worse than 82% of steel grades
- Limited ductility — 13%, worse than 78% of steel grades
CP800 properties
Typical room-temperature values for CP800-CR; bars are the position among steel grades.
Physical3
CP800 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 has a yield strength of 620 MPa (89.9 ksi) and a tensile strength of 840 MPa (122 ksi) — stronger than 78% of steel grades. Elongation at break is 13% and the elastic modulus is 210 GPa (30.5 Msi).
Thermal6
CP800 is rated for continuous service to 200°C (392 °F). It conducts heat at 38 W/m·K (22 BTU/hr·ft·°F), worse than 69% of steel grades. Thermal expansion is 12 µm/m·K (6.67 µin/in·°F).
Electrical3
CP800 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 CP800 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's machinability is fair (35/100, worse than 84% of steel grades); weldability very good (70/100); formability fair (45/100).
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. CP800 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with CP800
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.
Manufacturability
The process limits FabDigit applies to CP800. Every CP800 part is priced by an engineer; design inside these and the quote comes back without a redesign loop.
Sheet metal
| Formability | Better45 / 100 |
|---|---|
| Weldability | Better70 / 100 |
| Bendable | Yes |
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 |
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.
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
Black / Phosphate
Thermal Spray
How much does CP800 cost?
CP800 is a standard-cost steel ($$), cheaper than about 61% 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.
CP800 — frequently asked
What is CP800 used for?
CP800 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?
CP800 has a typical yield strength of 620 MPa (89.9 ksi) and a tensile strength of 840 MPa (122 ksi) — stronger than 78% of steel grades. Strength varies by condition: see the 2 listed tempers.
Is CP800 easy to machine?
Not especially — machinability is rated fair (35/100, worse than 84% 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 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?
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 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?
CP800 is rated for continuous use to about 200°C (392 °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.
How much does CP800 cost?
CP800 is a standard-cost steel ($$), cheaper than about 61% 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 CP800?
Yes — CP800 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; 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.