Steel CRS · finish state
Steel CRS HRPO
Properties of the HRPO condition, compared with the other CRS tempers.
Choose when you want hot-rolled economy but a clean, scale-free surface ready to weld, form or paint.
What is CRS HRPO?
CRS HRPO is CRS supplied in the HRPO condition — choose when you want hot-rolled economy but a clean, scale-free surface ready to weld, form or paint. CRS HRPO has a yield strength of 245 MPa (35.5 ksi) and a tensile strength of 360 MPa (52.2 ksi) — weaker than 95% of steel grades. Elongation at break is 33% and the elastic modulus is 200 GPa (29 Msi). CRS HRPO has a density of 7.87 g/cm³ (0.284 lb/in³), heavier than 91% of steel grades. It melts at 1,495°C (2,723 °F). HR is the default condition FabDigit quotes; HRPO is available on request or by drawing note.
Advantages
- High electrical conductivity — 12 % IACS, better than 100% of steel grades
- Readily welded — 96/100, better than 100% of steel grades
- Conducts heat well — 52 W/m·K (30 BTU/hr·ft·°F), better than 98% of steel grades
- Ductile — tolerates forming and impact — 33%, better than 96% of steel grades
- Forms and bends easily — 82/100, better than 94% of steel grades
Limitations
- Low strength — 245 MPa (35.5 ksi), worse than 95% of steel grades
- Hard to polish — 45/100, worse than 84% of steel grades
CRS HRPO properties
Typical room-temperature values for CRS HRPO — 9 properties are specific to this condition; the rest are grade-level values shared by every CRS temper. Each bar shows where the value sits among the steel grades in FabDigit's library — further right is higher.
Physical3
CRS HRPO has a density of 7.87 g/cm³ (0.284 lb/in³), heavier than 91% of steel grades. It melts at 1,495°C (2,723 °F).
Mechanical16
CRS HRPO has a yield strength of 245 MPa (35.5 ksi) and a tensile strength of 360 MPa (52.2 ksi) — weaker than 95% of steel grades. Elongation at break is 33% and the elastic modulus is 200 GPa (29 Msi).
Thermal6
CRS HRPO is rated for continuous service to 400°C (752 °F). It conducts heat at 52 W/m·K (30 BTU/hr·ft·°F), better than 98% of steel grades. Thermal expansion is 12.2 µm/m·K (6.78 µin/in·°F).
Electrical3
CRS HRPO conducts electricity at 12 % IACS, better than 100% of steel grades.
Chemical & Environmental3
Corrosion resistance is not recommended (10/100), worse than 87% of steel grades.
Sustainability4
Producing a kilogram of CRS HRPO takes about 25 MJ of energy and emits 2.1 kg of CO₂ — less than 82% of steel grades. Typical recycled content is 25%.
Manufacturability7
CRS HRPO's machinability is fair (52/100, better than 52% of steel grades); weldability excellent (96/100); formability very good (82/100).
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
Other CRS tempers and conditions
CRS is also supplied in 9 other conditions. The full side-by-side table is on the CRS overview.
- HRDefaultCheapest form for weldments, thicker plate and parts that will be painted or machined all over.250 MPa yield · 110 HB
- CR-FHUse for flat springy panels, roll-formed sections and slit strip where strength beats formability.560 MPa yield · 180 HB
- CarburizedPick when a cheap low-carbon part needs a wear-resistant surface over a tough, ductile core.420 MPa yield · 60 HRC
- CDBar-form equivalent of CRS: use for shafts, pins and machined parts needing straightness and a bright finish.370 MPa yield · 130 HB
- HRPOChoose when you want hot-rolled economy but a clean, scale-free surface ready to weld, form or paint.245 MPa yield · 105 HB
- GalvanizedUse for outdoor or humid-environment sheet metal where a sacrificial zinc layer replaces paint.240 MPa yield · 100 HB
- GAPick when a galvanized part must be painted or spot-welded: the matte Zn-Fe coating takes paint far better than spangled GI.235 MPa yield · 52 HRB
- CRDefault stock: smooth matte grey sheet with tight thickness tolerance for stamped brackets, enclosures and painted parts.220 MPa yield · 95 HB
- AnnealedUse dead-soft annealed stock for the most severe bending, spinning or hand-forming work.180 MPa yield · 86 HB
- CR-DDSPick when the part needs severe stamping or deep draws without splitting or orange-peel.170 MPa yield · 85 HB
Working with CRS HRPO
Is CRS easy to machine?
Machines easily but gummy — use positive-rake sharp tooling, high speed and flood coolant to avoid built-up edge and burrs; annealed stock gives poorer finish than cold drawn.
Can CRS be welded?
Excellent by MIG/TIG/spot/stick with ER70S-6 or E7018, no preheat or PWHT for thin sheet; grind mill scale on HR and expect zinc fume/porosity on galvanized.
Can CRS be formed, bent or molded?
Very good cold formability — CS grade handles most bends and stampings, DDS/IF grades for deep draws; minimum bend radius roughly 0.5–1× thickness across the rolling direction.
What surface finishes work on CRS?
Must be protected: zinc phosphate + powder/e-coat, zinc or electroless nickel plating, or oil for storage; not anodizable, and bare surfaces flash-rust within hours in humid air.
CRS 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 |
|---|---|---|
| CASTM A1008 CS Type B; ≤0.15 for some CS types | ≤ 0.1 | 0.06 |
| Mn | ≤ 0.6 | 0.35 |
| P | ≤ 0.03 | 0.02 |
| S | ≤ 0.04 | 0.02 |
| SiAl-killed/IF grades lower | ≤ 0.1 | 0.03 |
| Alaluminium-killed deoxidation | 0.02 – 0.07 | 0.04 |
| Fe | balance | — |
CRS HRPO — frequently asked
What is CRS HRPO used for?
CRS HRPO is typically used for stamped enclosures, brackets and furniture frames. In short: standard cold-rolled sheet.
What is the yield strength of CRS HRPO?
CRS HRPO has a typical yield strength of 245 MPa (35.5 ksi) and a tensile strength of 360 MPa (52.2 ksi) — weaker than 95% of steel grades. Strength varies by condition: see the 10 listed tempers.
Is CRS HRPO easy to machine?
Reasonably — machinability is rated fair (52/100, better than 52% of steel grades). Machines easily but gummy — use positive-rake sharp tooling, high speed and flood coolant to avoid built-up edge and burrs; annealed stock gives poorer finish than cold drawn.
Can CRS HRPO be welded?
Yes — weldability is rated excellent (96/100). Excellent by MIG/TIG/spot/stick with ER70S-6 or E7018, no preheat or PWHT for thin sheet; grind mill scale on HR and expect zinc fume/porosity on galvanized.
What surface finishes work on CRS HRPO?
Must be protected: zinc phosphate + powder/e-coat, zinc or electroless nickel plating, or oil for storage; not anodizable, and bare surfaces flash-rust within hours in humid air.
Can CRS HRPO be formed, bent or molded?
Very good cold formability — CS grade handles most bends and stampings, DDS/IF grades for deep draws; minimum bend radius roughly 0.5–1× thickness across the rolling direction.
What is the maximum service temperature of CRS HRPO?
CRS HRPO 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 CRS-HR and CRS CR-FH?
HR is the default condition — cheapest form for weldments, thicker plate and parts that will be painted or machined all over. CR-FH: use for flat springy panels, roll-formed sections and slit strip where strength beats formability. Yield strength is 250 MPa in HR versus 560 MPa in CR-FH.
Can FabDigit make parts in CRS HRPO?
Yes — CRS HRPO 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
- ASTM A1008/A1008M — Cold-Rolled Carbon Steel Sheet — ASTM International (2021)
- ASTM A1011/A1011M — Hot-Rolled Carbon Steel Sheet and Strip — ASTM International (2018)
- ASTM A653/A653M — Zinc-Coated (Galvanized) and Zinc-Iron Alloy-Coated Sheet — ASTM International (2020)
- GB/T 5213 / GB/T 700 Q235B (2019)
- ASM Handbook Vol.1 — Properties and Selection: Irons, Steels — ASM International (1990)
- Machinery's Handbook, 31st ed. (machinability ratings) — Industrial Press (2020)
- worldsteel LCI data for steel products — World Steel Association (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.