Steel A53 Grade B
ASTM A53 Grade B · UNS K02504
A53 Grade B (UNS K02504) is a general-purpose carbon steel pipe made seamless or electric-resistance welded, supplied hot-rolled black, cold-drawn, normalized or hot-dip galvanized.
Reference datasheet — A53 Grade B is not in the instant-quote catalog. Upload your part and an engineer will quote it in this grade or suggest the closest stocked equivalent.
Values for the S-HR-BLK condition
A53 Grade B tempers and conditions
A53 Grade B is supplied in 4 conditions, soft to hard. S-HR-BLK is the default FabDigit quotes; the values on this page are for it.
Compare all 4 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Normalized | Supplementary condition for uniform fine-grain structure, better toughness and lower residual stress before bending or impact-tested service. | 275 | 450 | 33 | 131 HB | 10 % IACS |
Type E | Lowest-cost route for larger diameters and thinner walls; weld seam is normalized locally, mechanicals match Grade B minima. | 295 | 460 | 28 | 140 HB | 10 % IACS |
S-HR-BLKDefault seamless, hot finished, black (plain end) | Default stock condition: hot-finished seamless black pipe for general pressure, mechanical and structural piping. | 300 | 470 | 30 | 143 HB | — |
Cold-drawn seamless | Choose for tight tolerance and smooth bore mechanical tubing; strength and hardness rise, ductility and bendability fall. | 390 | 500 | 16 | 170 HB | 10 % IACS |
Supply forms, finishes and certifications
Ways A53 Grade B is supplied — form, process route, surface or paperwork — without a datasheet of their own. The property values above apply.
| Option | What it is | Type |
|---|---|---|
GALV | Hot-dip galvanized | Surface finish |
What is A53 Grade B?
A53 Grade B (UNS K02504) is a general-purpose carbon steel pipe made seamless or electric-resistance welded, supplied hot-rolled black, cold-drawn, normalized or hot-dip galvanized. It delivers 300 MPa yield, 470 MPa tensile, 30 % elongation and about 143 HB with service to 425 °C, and is the low-cost standard for mechanical, low-pressure and structural piping in threaded, grooved or welded systems. Bare pipe has essentially no corrosion resistance (score 10) and the welded product is not the choice for demanding high-temperature pressure service. Use A106 Grade B seamless pipe where code high-temperature piping is required. A53 Grade B has a density of 7.85 g/cm³ (0.284 lb/in³), heavier than 56% of steel grades. It melts at 1,425°C (2,597 °F). A53 Grade B has a yield strength of 300 MPa (43.5 ksi) and a tensile strength of 470 MPa (68.2 ksi) — weaker than 86% of steel grades. Elongation at break is 30% and the elastic modulus is 200 GPa (29 Msi).
What is A53 Grade B used for?
- water piping
- structural pipe
- low-pressure lines
- fencing/scaffolding tube
Advantages
- Ductile — tolerates forming and impact — 30%, better than 93% of steel grades
- Readily welded — 92/100, better than 93% of steel grades
- Low embodied carbon — 1.9 kg CO₂/kg, better than 92% of steel grades
- Forms and bends easily — 75/100, better than 90% of steel grades
- Conducts heat well — 50 W/m·K (28.9 BTU/hr·ft·°F), better than 87% of steel grades
Limitations
- Low strength — 300 MPa (43.5 ksi), worse than 86% of steel grades
- Hard to polish — 45/100, worse than 84% of steel grades
A53 Grade B properties
Typical room-temperature values for A53 Grade B-S-HR-BLK; bars are the position among steel grades.
Physical3
A53 Grade B has a density of 7.85 g/cm³ (0.284 lb/in³), heavier than 56% of steel grades. It melts at 1,425°C (2,597 °F).
Mechanical16
A53 Grade B has a yield strength of 300 MPa (43.5 ksi) and a tensile strength of 470 MPa (68.2 ksi) — weaker than 86% of steel grades. Elongation at break is 30% and the elastic modulus is 200 GPa (29 Msi).
Thermal6
A53 Grade B is rated for continuous service to 425°C (797 °F). It conducts heat at 50 W/m·K (28.9 BTU/hr·ft·°F), better than 87% of steel grades. Thermal expansion is 11.7 µm/m·K (6.5 µin/in·°F).
Electrical3
A53 Grade B conducts electricity at 10 % IACS, better than 83% of steel grades.
Chemical & Environmental3
Corrosion resistance is not recommended (10/100), worse than 86% of steel grades.
Sustainability4
Producing a kilogram of A53 Grade B takes about 25 MJ of energy and emits 1.9 kg of CO₂ — less than 82% of steel grades. Typical recycled content is 30%.
Manufacturability7
A53 Grade B's machinability is good (60/100, better than 83% of steel grades); weldability excellent (92/100); formability very good (75/100).
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. A53 Grade B is highlighted; hover a dot for its name, or open the interactive family chart.
Working with A53 Grade B
Is A53 Grade B easy to machine?
Machines and threads easily (NPT per ASME B1.20.1) at ~65 % of 1212; use sharp tooling and coolant since the low-carbon matrix is gummy and produces stringy chips.
Can A53 Grade B be welded?
Excellent weldability by SMAW/GTAW/GMAW with E6010/E7018 or ER70S-2/6 filler; no preheat needed below ~25 mm wall, but grind off galvanizing and provide fume extraction on coated pipe.
Can A53 Grade B be formed, bent or molded?
Cold bends readily to 3–5 D on a mandrel bender; hot bending or induction bending at 850–950 °C for tight radii, follow with normalizing if heavily strained.
A53 Grade B 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 |
|---|---|---|
| CType S and Type E, Grade B | ≤ 0.3 | 0.2 |
| Mn | ≤ 1.2 | 0.9 |
| P | ≤ 0.05 | 0.02 |
| S | ≤ 0.05 | 0.02 |
| Cucombined alloy limit applies | ≤ 0.4 | 0.15 |
| Ni | ≤ 0.4 | 0.1 |
| Cr | ≤ 0.4 | 0.1 |
| Mo | ≤ 0.15 | 0.03 |
| V | ≤ 0.08 | 0.02 |
| Fe | balance |
What surface finishes work on A53 Grade B?
Supplied black (mill scale or varnish) or hot-dip galvanized to ASTM A123; otherwise blast to SA 2.5 and apply zinc-rich primer, epoxy or FBE coating — no anodizing possible.
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).
Organic Coating
Black / Phosphate
Thermal Spray
Equivalent designations
Standards and trade names that resolve to Steel A53 Grade B in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- UNS
- K02504
- ASTM
- A53 Gr B
How much does A53 Grade B cost?
A53 Grade B is a budget-cost steel ($), cheaper than about 90% 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.
A53 Grade B — frequently asked
What is A53 Grade B used for?
A53 Grade B is typically used for water piping, structural pipe, low-pressure lines and fencing/scaffolding tube. In short: low-cost general-purpose pipe; threadable and galvanizable; seamless or welded supply.
What is the yield strength of A53 Grade B?
A53 Grade B has a typical yield strength of 300 MPa (43.5 ksi) and a tensile strength of 470 MPa (68.2 ksi) — weaker than 86% of steel grades. Strength varies by condition: see the 4 listed tempers.
Is A53 Grade B easy to machine?
Reasonably — machinability is rated good (60/100, better than 83% of steel grades). Machines and threads easily (NPT per ASME B1.20.1) at ~65 % of 1212; use sharp tooling and coolant since the low-carbon matrix is gummy and produces stringy chips.
Can A53 Grade B be welded?
Yes — weldability is rated excellent (92/100). Excellent weldability by SMAW/GTAW/GMAW with E6010/E7018 or ER70S-2/6 filler; no preheat needed below ~25 mm wall, but grind off galvanizing and provide fume extraction on coated pipe.
What surface finishes work on A53 Grade B?
Supplied black (mill scale or varnish) or hot-dip galvanized to ASTM A123; otherwise blast to SA 2.5 and apply zinc-rich primer, epoxy or FBE coating — no anodizing possible.
Can A53 Grade B be formed, bent or molded?
Cold bends readily to 3–5 D on a mandrel bender; hot bending or induction bending at 850–950 °C for tight radii, follow with normalizing if heavily strained.
What is the maximum service temperature of A53 Grade B?
A53 Grade B 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.
What is the difference between A53 Grade B S-HR-BLK and A53 Grade B S-CD?
S-HR-BLK is the default condition — default stock condition: hot-finished seamless black pipe for general pressure, mechanical and structural piping. S-CD: choose for tight tolerance and smooth bore mechanical tubing; strength and hardness rise, ductility and bendability fall. Yield strength is 300 MPa in S-HR-BLK versus 390 MPa in S-CD.
How much does A53 Grade B cost?
A53 Grade B is a budget-cost steel ($), cheaper than about 90% 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.
Sources
- ASTM A53/A53M Standard Specification for Pipe, Steel, Black and Hot-Dipped, Zinc-Coated, Welded and Seamless — ASTM International (2020)
- ASME B31.3 Process Piping / B31.1 Power Piping allowable stress tables — ASME (2022)
- 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, machinability ratings — Industrial Press (2020)
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.