Steel HRS
HRS is plain low-carbon (mild) hot-rolled steel, the ASTM A36 / A1011 CS and Q235B class of ordinary carbon structural steel, offering roughly 250–300 MPa yield (285 MPa on file), 450 MPa tensile, 23 % elongation and 130 HB at the lowest cost per kilogram.
Values for the HR condition
HRS tempers and conditions
HRS is supplied in 3 conditions, soft to hard. HR is the default FabDigit quotes; the values on this page are for it.
Compare all 3 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Hot Rolled, Pickled & Oiled | Choose when you want hot-rolled price and gauge but a clean, paint- or weld-ready surface without shot blasting. | 280 | 440 | 26 | 125 HB | — |
HRDefault Hot rolled | Cheapest structural condition — pick for weldments, frames, brackets and plate where dimensional tolerance and surface finish don't matter. | 285 | 450 | 23 | 130 HB | — |
Cold rolled | Pick for tight thickness tolerance, smooth paint-ready surface and better machined finish; costs more and has less ductility than HR. | 350 | 450 | 18 | 145 HB | — |
Supply forms, finishes and certifications
Ways HRS 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 |
Galvanized | Hot-dip zinc coated | Coating |
What is HRS?
HRS is plain low-carbon (mild) hot-rolled steel, the ASTM A36 / A1011 CS and Q235B class of ordinary carbon structural steel, offering roughly 250–300 MPa yield (285 MPa on file), 450 MPa tensile, 23 % elongation and 130 HB at the lowest cost per kilogram. Engineers specify it for plate, sections, base plates, brackets and welded frames because of its near-perfect weldability (score 95) and easy cold bending, accepting wide thickness tolerances and a mill-scale surface. It has essentially no corrosion resistance (score 10), so paint, zinc plating or galvanizing is mandatory, it cannot be strengthened by heat treatment, and low-temperature impact toughness is not guaranteed. Cold-rolled or HRPO sheet is the nearest alternative when surface finish and tolerance matter. HRS has a density of 7.85 g/cm³ (0.284 lb/in³), heavier than 56% of steel grades. It melts at 1,495°C (2,723 °F). HRS has a yield strength of 285 MPa (41.3 ksi) and a tensile strength of 450 MPa (65.3 ksi) — weaker than 89% of steel grades. Elongation at break is 23% and the elastic modulus is 200 GPa (29 Msi).
What is HRS used for?
- Structural plate and base plates
- Bracket weldments
- Welded machine frames and skids
- Sheet-metal enclosures and panels
- Formed channels, angles and gussets
- Machine guards and platform floor plate
- Galvanized outdoor supports
Advantages
- Readily welded — 95/100, better than 97% of steel grades
- Conducts heat well — 51.9 W/m·K (30 BTU/hr·ft·°F), better than 96% of steel grades
- High electrical conductivity — 10.8 % IACS, better than 94% of steel grades
- Forms and bends easily — 65/100, better than 81% of steel grades
Limitations
- Hard to polish — 40/100, worse than 96% of steel grades
- Low strength — 285 MPa (41.3 ksi), worse than 89% of steel grades
HRS properties
Typical room-temperature values for HRS-HR; bars are the position among steel grades.
Physical3
HRS has a density of 7.85 g/cm³ (0.284 lb/in³), heavier than 56% of steel grades. It melts at 1,495°C (2,723 °F).
Mechanical16
HRS has a yield strength of 285 MPa (41.3 ksi) and a tensile strength of 450 MPa (65.3 ksi) — weaker than 89% of steel grades. Elongation at break is 23% and the elastic modulus is 200 GPa (29 Msi).
Thermal6
HRS is rated for continuous service to 400°C (752 °F). It conducts heat at 51.9 W/m·K (30 BTU/hr·ft·°F), better than 96% of steel grades. Thermal expansion is 11.9 µm/m·K (6.61 µin/in·°F).
Electrical3
HRS conducts electricity at 10.8 % IACS, better than 94% of steel grades.
Chemical & Environmental3
Corrosion resistance is not recommended (10/100), worse than 86% of steel grades.
Sustainability4
Producing a kilogram of HRS 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
HRS's machinability is good (60/100, better than 83% of steel grades); weldability excellent (95/100); formability good (65/100).
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. HRS is highlighted; hover a dot for its name, or open the interactive family chart.
Working with HRS
Is HRS easy to machine?
Free and easy at HSS/carbide speeds but gummy — use positive rake, sharp tooling and coolant; expect a poorer finish than cold-rolled or leaded grades and remove mill scale first to protect edges.
Can HRS be welded?
Prequalified for essentially all processes (SMAW/GMAW/FCAW/RSW) with E70/ER70S-6 consumables, no preheat below ~38 mm at RT; grind off scale, oil or zinc coating before welding and ventilate zinc fume.
Can HRS be formed, bent or molded?
Bends and rolls readily cold (min bend radius ≈ 1–1.5 t hot rolled, 0.5–1 t cold rolled); hot-rolled scale can crack and mark dies, and springback is low.
Manufacturability
The process limits FabDigit applies to HRS. Every HRS part is priced by an engineer; design inside these and the quote comes back without a redesign loop.
CNC machining
| Machinability | Better60 / 100 |
|---|---|
| ISO material group | P.2 |
| Cutting speed (rough / finish) | 180 / 210 m/min |
| Minimum wall | 0.8 mm |
| Minimum internal radius | 1 mm |
| Drill depth limit | 5× diameter |
| Best surface (machined / polished) | Ra 1.6 / — |
| Hardenable after machining | No |
Sheet metal
| Formability | Excellent65 / 100 |
|---|---|
| Weldability | Excellent95 / 100 |
| Bendable | Yes |
HRS 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 |
|---|---|---|
| CA36 plate ≤0.26; A1011 CS / Q235B typically 0.12–0.20 | ≤ 0.26 | 0.18 |
| Mnwider range for thicker plate | 0.3 – 1.2 | 0.7 |
| Si0.15–0.40 when silicon-killed | ≤ 0.4 | 0.2 |
| P | ≤ 0.04 | 0.02 |
| S | ≤ 0.05 | 0.02 |
| Cu0.20 min if copper-bearing grade specified | ≤ 0.2 | 0.05 |
| Febalance, residual Cr/Ni/Mo typically <0.1 each | balance |
What surface finishes work on HRS?
No anodizing — blast or pickle then prime; typical finishes are phosphate + powder coat/e-coat, zinc plating, hot-dip galvanizing or black oxide/oil for temporary protection.
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
CVD Coating
Black / Phosphate
Thermal Spray
Equivalent designations
Standards and trade names that resolve to Steel HRS in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- Also called
- Hot Rolled Steel
How much does HRS cost?
HRS is a standard-cost steel ($$), cheaper than about 71% 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.
HRS — frequently asked
What is HRS used for?
HRS is typically used for structural plate and base plates, bracket weldments, welded machine frames and skids, sheet-metal enclosures and panels, formed channels, angles and gussets and machine guards and platform floor plate. In short: workhorse hot-rolled plate.
What is the yield strength of HRS?
HRS has a typical yield strength of 285 MPa (41.3 ksi) and a tensile strength of 450 MPa (65.3 ksi) — weaker than 89% of steel grades. Strength varies by condition: see the 3 listed tempers.
Is HRS easy to machine?
Reasonably — machinability is rated good (60/100, better than 83% of steel grades). Free and easy at HSS/carbide speeds but gummy — use positive rake, sharp tooling and coolant; expect a poorer finish than cold-rolled or leaded grades and remove mill scale first to protect edges.
Can HRS be welded?
Yes — weldability is rated excellent (95/100). Prequalified for essentially all processes (SMAW/GMAW/FCAW/RSW) with E70/ER70S-6 consumables, no preheat below ~38 mm at RT; grind off scale, oil or zinc coating before welding and ventilate zinc fume.
What surface finishes work on HRS?
No anodizing — blast or pickle then prime; typical finishes are phosphate + powder coat/e-coat, zinc plating, hot-dip galvanizing or black oxide/oil for temporary protection.
Can HRS be formed, bent or molded?
Bends and rolls readily cold (min bend radius ≈ 1–1.5 t hot rolled, 0.5–1 t cold rolled); hot-rolled scale can crack and mark dies, and springback is low.
What is the maximum service temperature of HRS?
HRS 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 HRS-HR and HRS-CR?
HR is the default condition — cheapest structural condition — pick for weldments, frames, brackets and plate where dimensional tolerance and surface finish don't matter. CR: pick for tight thickness tolerance, smooth paint-ready surface and better machined finish; costs more and has less ductility than HR. Yield strength is 285 MPa in HR versus 350 MPa in CR.
How much does HRS cost?
HRS is a standard-cost steel ($$), cheaper than about 71% 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 HRS?
Yes — HRS 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
- ASTM A36/A36M Carbon Structural Steel — ASTM International (2019)
- ASTM A1011/A1011M Hot-Rolled Sheet and Strip, CS/SS/HSLAS — ASTM International (2018)
- ASTM A1008/A1008M Cold-Rolled Sheet, CS/SS/HSLAS — ASTM International (2021)
- ASTM A653/A653M Zinc-Coated (Galvanized/Galvannealed) Sheet — ASTM International (2020)
- GB/T 700 (Q235B) — SAC / (2006)
- 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; 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.