Steel Q235A · supply condition · default condition
Steel Q235A-HR
Properties of the HR condition, compared with the other Q235A tempers.
Default stock condition for plate, angle, channel, I-beam and hot-rolled coil in general welded structures.
What is Q235A-HR?
Q235A-HR is Q235A supplied in the HR condition — default stock condition for plate, angle, channel, I-beam and hot-rolled coil in general welded structures. Q235A-HR has a yield strength of 255 MPa (37 ksi) and a tensile strength of 420 MPa (60.9 ksi) — weaker than 93% of steel grades. Elongation at break is 28% and the elastic modulus is 206 GPa (29.9 Msi). Q235A-HR 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).
Advantages
- Forms and bends easily — 82/100, better than 94% of steel grades
- Easy to machine — 65/100, better than 93% of steel grades
- Readily welded — 92/100, better than 93% of steel grades
- High electrical conductivity — 10.5 % IACS, better than 89% of steel grades
- Ductile — tolerates forming and impact — 28%, better than 88% of steel grades
Limitations
- Low strength — 255 MPa (37 ksi), worse than 93% of steel grades
- Hard to polish — 45/100, worse than 84% of steel grades
- Low fracture toughness — 60 MPa·√m (54.6 ksi·√in), worse than 79% of steel grades
Q235A-HR properties
Typical room-temperature values for Q235A-HR — 11 properties are specific to this condition; the rest are grade-level values shared by every Q235A temper. Each bar shows where the value sits among the steel grades in FabDigit's library — further right is higher.
Physical3
Q235A-HR 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
Q235A-HR has a yield strength of 255 MPa (37 ksi) and a tensile strength of 420 MPa (60.9 ksi) — weaker than 93% of steel grades. Elongation at break is 28% and the elastic modulus is 206 GPa (29.9 Msi).
Thermal6
Q235A-HR is rated for continuous service to 350°C (662 °F). It conducts heat at 50 W/m·K (28.9 BTU/hr·ft·°F), better than 88% of steel grades. Thermal expansion is 11.9 µm/m·K (6.61 µin/in·°F).
Electrical3
Q235A-HR conducts electricity at 10.5 % IACS, better than 89% of steel grades.
Chemical & Environmental3
Corrosion resistance is not recommended (10/100), worse than 87% of steel grades.
Sustainability4
Producing a kilogram of Q235A-HR takes about 25 MJ of energy and emits 2.1 kg of CO₂ — less than 82% of steel grades. Typical recycled content is 20%.
Manufacturability7
Q235A-HR's machinability is good (65/100, better than 93% of steel grades); weldability excellent (92/100); formability very good (82/100).
Common Calculations5
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
Other Q235A tempers and conditions
Q235A is also supplied in 4 other conditions. The full side-by-side table is on the Q235A overview.
- HRDefaultDefault stock condition for plate, angle, channel, I-beam and hot-rolled coil in general welded structures.255 MPa yield · 131 HB
- CDPick for shafts, pins and machined parts where higher yield, straightness and a bright as-drawn surface save machining.400 MPa yield · 163 HB
- CRChoose for thin gauge sheet parts needing tight thickness tolerance, flat clean surface and paint-ready finish.340 MPa yield · 150 HB
Working with Q235A-HR
Is Q235A easy to machine?
Machines easily but gummy in the hot-rolled state — use positive-rake carbide, high speed and generous coolant; cold-drawn stock gives cleaner chips and better finish.
Can Q235A be welded?
Excellent weldability by SMAW/GMAW/SAW with E43xx (E4303/E4315) or ER70S-6, no preheat below ~30 mm; grade A's high S/P raises hot-cracking risk on thick restrained joints, so prefer Q235B for critical welds.
Can Q235A be formed, bent or molded?
Readily bent, rolled and press-formed cold at bend radii ≥1–1.5 t; hot forming 850–1050 °C, and avoid cold bending below 0 °C.
What surface finishes work on Q235A?
Must be protected — shot-blast then prime/paint, hot-dip galvanize or zinc-plate/phosphate; takes oil-blackening and powder coat well, but polished surfaces rust within hours.
Q235A 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 |
|---|---|---|
| CGB/T 700-2006, grade A | 0.14 – 0.22 | 0.18 |
| Si | ≤ 0.35 | 0.2 |
| Mntypically 0.30–0.65 in plate | ≤ 1.4 | 0.5 |
| P | ≤ 0.05 | 0.03 |
| Sloosest S limit of the Q235 quality grades | ≤ 0.05 | 0.03 |
| Fe | balance | — |
Q235A-HR — frequently asked
What is Q235A-HR used for?
Q235A-HR is typically used for building frames and columns, structural beams, angle and channel, welded frames and skids, base plates and gussets, laser-cut sheet parts and enclosures, cabinets and machine guards. In short: chinese mild-steel sheet.
What is the yield strength of Q235A-HR?
Q235A-HR has a typical yield strength of 255 MPa (37 ksi) and a tensile strength of 420 MPa (60.9 ksi) — weaker than 93% of steel grades. Strength varies by condition: see the 5 listed tempers.
Is Q235A-HR easy to machine?
Reasonably — machinability is rated good (65/100, better than 93% of steel grades). Machines easily but gummy in the hot-rolled state — use positive-rake carbide, high speed and generous coolant; cold-drawn stock gives cleaner chips and better finish.
Can Q235A-HR be welded?
Yes — weldability is rated excellent (92/100). Excellent weldability by SMAW/GMAW/SAW with E43xx (E4303/E4315) or ER70S-6, no preheat below ~30 mm; grade A's high S/P raises hot-cracking risk on thick restrained joints, so prefer Q235B for critical welds.
What surface finishes work on Q235A-HR?
Must be protected — shot-blast then prime/paint, hot-dip galvanize or zinc-plate/phosphate; takes oil-blackening and powder coat well, but polished surfaces rust within hours.
Can Q235A-HR be formed, bent or molded?
Readily bent, rolled and press-formed cold at bend radii ≥1–1.5 t; hot forming 850–1050 °C, and avoid cold bending below 0 °C.
What is the maximum service temperature of Q235A-HR?
Q235A-HR 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 Q235A-HR and Q235A-CD?
HR is the default condition — default stock condition for plate, angle, channel, I-beam and hot-rolled coil in general welded structures. CD: pick for shafts, pins and machined parts where higher yield, straightness and a bright as-drawn surface save machining. Yield strength is 255 MPa in HR versus 400 MPa in CD.
Can FabDigit make parts in Q235A-HR?
Yes — Q235A-HR 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
- ASM Handbook Vol.1: Properties and Selection — Irons, Steels — ASM International (1990)
- ASM Handbook Vol.19: Fatigue and Fracture — ASM International (1996)
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.