Steel A285
ASTM A285
A285 is a low- to intermediate-tensile-strength carbon steel plate qualified for pressure vessel service, available as Grades A, B and C and equivalent to Q245R.
Values for the HR condition
A285 tempers and conditions
A285 is supplied in 8 conditions, soft to hard. HR is the default FabDigit quotes; the values on this page are for it.
Compare all 8 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Grade A | Softest, most weldable and most formable A285 grade; pick it for deeply dished heads and low design-pressure tanks. | 190 | 350 | 30 | 110 HB | 10.8 % IACS |
Grade B | Middle strength/ductility compromise when Grade A is too weak but full Grade C carbon is unwelcome for welding. | 215 | 400 | 28 | 120 HB | 10.5 % IACS |
full or subcritical anneal / stress relieved | Choose when maximum ductility and lowest residual stress are needed for severe cold forming or after heavy weld fabrication (PWHT). | 225 | 415 | 34 | 118 HB | 10.8 % IACS |
Grade C | Most commonly stocked A285 grade; use for the highest allowable stress of the specification in storage tanks and low-pressure vessels. | 240 | 440 | 27 | 130 HB | 10.1 % IACS |
HRDefault Hot rolled | Standard stock condition for A285 pressure-vessel plate; take it for ordinary welded tanks and boiler shells with no low-temperature requirement. | 250 | 450 | 30 | 130 HB | — |
Normalized and tempered | Normalize plus a high temper to soften/stabilize the plate; used when both toughness and dimensional/residual-stress stability are required. | 255 | 440 | 32 | 128 HB | 10.8 % IACS |
austenitized ~900 °C, air cooled | Specify for heavier plate or when uniform fine grain and better notch toughness are wanted (supplementary impact testing). | 260 | 455 | 31 | 132 HB | 10.8 % IACS |
Quenched and tempered | Rarely used for A285 (carbon too low for real hardenability); ordered only where slightly higher yield and best low-temperature toughness are needed in thin plate. | 320 | 490 | 27 | 145 HB | 10.5 % IACS |
What is A285?
A285 is a low- to intermediate-tensile-strength carbon steel plate qualified for pressure vessel service, available as Grades A, B and C and equivalent to Q245R. Typical plate shows about 250 MPa yield, 450 MPa tensile, 30 % elongation and 130 HB, and is chosen for boilers, storage tanks and petrochemical vessels where weldability and cold formability matter more than strength. Service is limited to roughly 425 °C, the steel has no corrosion resistance and must be painted or lined, and higher-pressure or thicker designs usually move to A516 Grade 70. A285 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). A285 has a yield strength of 250 MPa (36.3 ksi) and a tensile strength of 450 MPa (65.3 ksi) — weaker than 94% of steel grades. Elongation at break is 30% and the elastic modulus is 200 GPa (29 Msi).
What is A285 used for?
- Boilers
- Storage tanks
- Petrochemical vessels
Advantages
- Easy to machine — 68/100, better than 95% of steel grades
- High electrical conductivity — 10.8 % IACS, better than 94% of steel grades
- Forms and bends easily — 82/100, better than 94% of steel grades
- Ductile — tolerates forming and impact — 30%, better than 93% of steel grades
- Readily welded — 92/100, better than 93% of steel grades
Limitations
- Hard to polish — 40/100, worse than 96% of steel grades
- Low strength — 250 MPa (36.3 ksi), worse than 94% of steel grades
A285 properties
Typical room-temperature values for A285-HR; bars are the position among steel grades.
Physical3
A285 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).
Mechanical15
A285 has a yield strength of 250 MPa (36.3 ksi) and a tensile strength of 450 MPa (65.3 ksi) — weaker than 94% of steel grades. Elongation at break is 30% and the elastic modulus is 200 GPa (29 Msi).
Thermal6
A285 is rated for continuous service to 425°C (797 °F). It conducts heat at 51 W/m·K (29.5 BTU/hr·ft·°F), better than 92% of steel grades. Thermal expansion is 12 µm/m·K (6.67 µin/in·°F).
Electrical3
A285 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 A285 takes about 25 MJ of energy and emits 1.9 kg of CO₂ — less than 82% of steel grades. Typical recycled content is 25%.
Manufacturability7
A285's machinability is good (68/100, better than 95% 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.
Strength versus weight in the steel family
Yield strength against density for every steel grade FabDigit runs. A285 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with A285
Is A285 easy to machine?
Machines easily but gummy — use positive rake, sharp tools and generous coolant to avoid built-up edge and torn threads; drilling and plasma/oxy cutting are routine.
Can A285 be welded?
Excellent weldability by SMAW/GMAW/SAW with E70xx-class filler; no preheat below ~25 mm, preheat 100 °C for heavy sections, PWHT per ASME VIII when required by thickness or service.
Can A285 be formed, bent or molded?
Very good cold formability for shells, dished heads and rolled sections; hot form 900–1200 °C and re-normalize if cold strain exceeds code limits.
Manufacturability
The process limits FabDigit applies to A285. Every A285 part is priced by an engineer; design inside these and the quote comes back without a redesign loop.
CNC machining
| Machinability | Better68 / 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 | Better82 / 100 |
|---|---|
| Weldability | Excellent92 / 100 |
| Bendable | Yes |
A285 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 |
|---|---|---|
| Cheat analysis max: Gr A 0.17, Gr B 0.22, Gr C 0.28 | ≤ 0.28 | 0.2 |
| Mnheat analysis max (0.98 product analysis) | ≤ 0.9 | 0.6 |
| P | ≤ 0.04 | 0.02 |
| S | ≤ 0.04 | 0.01 |
| Sinot specified by A285; typical mill practice (killed/semi-killed) | ≤ 0.4 | 0.2 |
| Fe | balance |
What surface finishes work on A285?
No passive film — must be blast-cleaned and painted, epoxy-lined, galvanized or metallized; phosphate pretreatment improves paint adhesion.
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 A285 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- ASTM
- A285 Grade C
- Similar grades
- Q245R
How much does A285 cost?
A285 is a standard-cost steel ($$), cheaper than about 71% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
A285 — frequently asked
What is A285 used for?
A285 is typically used for boilers, storage tanks and petrochemical vessels. In short: pressure-vessel quality plate.
What is the yield strength of A285?
A285 has a typical yield strength of 250 MPa (36.3 ksi) and a tensile strength of 450 MPa (65.3 ksi) — weaker than 94% of steel grades. Strength varies by condition: see the 8 listed tempers.
Is A285 easy to machine?
Reasonably — machinability is rated good (68/100, better than 95% of steel grades). Machines easily but gummy — use positive rake, sharp tools and generous coolant to avoid built-up edge and torn threads; drilling and plasma/oxy cutting are routine.
Can A285 be welded?
Yes — weldability is rated excellent (92/100). Excellent weldability by SMAW/GMAW/SAW with E70xx-class filler; no preheat below ~25 mm, preheat 100 °C for heavy sections, PWHT per ASME VIII when required by thickness or service.
What surface finishes work on A285?
No passive film — must be blast-cleaned and painted, epoxy-lined, galvanized or metallized; phosphate pretreatment improves paint adhesion.
Can A285 be formed, bent or molded?
Very good cold formability for shells, dished heads and rolled sections; hot form 900–1200 °C and re-normalize if cold strain exceeds code limits.
What is the maximum service temperature of A285?
A285 is rated for continuous use to about 425°C (797 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
How much does A285 cost?
A285 is a standard-cost steel ($$), 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 A285?
Yes — A285 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 A285/A285M — Pressure Vessel Plates, Carbon Steel, Low- and Intermediate-Tensile Strength — ASTM International (2017)
- ASME BPVC Section II Part D — Properties (Metric) — ASME (2023)
- ASM Handbook Vol.1: Properties and Selection — Irons, Steels, and High-Performance Alloys — ASM International (1990)
- Machinery's Handbook, 31st ed. (machinability ratings) — Industrial Press (2020)
- GB/T 713 Q245R (comparable grade) — SAC (2014)
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.