Steel 20R
20R is a low-carbon pressure-vessel plate steel of the A516 Gr 60 class, supplied as-rolled, normalized, TMCP or normalized-and-stress-relieved, with Z35 through-thickness and HIC-resistant variants available.
Reference datasheet — 20R 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 AR condition
20R tempers and conditions
20R is supplied in 5 conditions, soft to hard. AR is the default FabDigit quotes; the values on this page are for it.
Compare all 5 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Normalized then stress-relieved / simulated PWHT | Condition for thick or heavily welded vessels requiring PWHT; slight strength drop must be allowed in design. | 255 | 445 | 33 | 120 HB | 10.8 % IACS |
Normalized | Mandatory for plate over ~36 mm and preferred where uniform fine grain and better low-temperature toughness are needed. | 265 | 455 | 32 | 125 HB | — |
Low-sulphur, Ca-treated HIC/wet-H₂S resistant plate | Choose for wet H₂S / sour service; S ≤ 0.003 %, inclusion-shape controlled and NACE TM0284 tested. | 265 | 450 | 33 | 125 HB | 10.8 % IACS |
ARDefault As hot-rolled plate | Standard stock condition for thin/medium 20R–Q245R vessel plate where no normalizing is required. | 275 | 460 | 30 | 130 HB | 10.8 % IACS |
Thermomechanically controlled processed | Controlled-rolled plate giving normalized-like fine grain without a separate furnace cycle; good toughness with lower carbon equivalent. | 290 | 470 | 32 | 130 HB | 10.8 % IACS |
Supply forms, finishes and certifications
Ways 20R is supplied — form, process route, surface or paperwork — without a datasheet of their own. The property values above apply.
| Option | What it is | Type |
|---|---|---|
Z35 | Through-thickness (Z-direction) quality plate, normalized | Certification |
What is 20R?
20R is a low-carbon pressure-vessel plate steel of the A516 Gr 60 class, supplied as-rolled, normalized, TMCP or normalized-and-stress-relieved, with Z35 through-thickness and HIC-resistant variants available. Default properties are 275 MPa yield, 460 MPa tensile, 30 % elongation and about 130 HB, with service to roughly 425 °C, and it is used mainly as plate for shells, heads and tank walls. A carbon equivalent near 0.35 gives excellent weldability and 1.5×t cold bending, but the steel has no corrosion resistance and needs coating, cladding or lining in wet service. For elevated-temperature boiler parts, 20G (A515 Gr 60) is the nearest alternative. 20R 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). 20R has a yield strength of 275 MPa (39.9 ksi) and a tensile strength of 460 MPa (66.7 ksi) — weaker than 91% of steel grades. Elongation at break is 30% and the elastic modulus is 206 GPa (29.9 Msi).
What is 20R used for?
- pressure vessel shells
- storage tanks
- process vessels
Advantages
- Readily welded — 95/100, better than 97% of steel grades
- Tough — resists crack growth — 140 MPa·√m (127.4 ksi·√in), better than 94% 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
Limitations
- Low strength — 275 MPa (39.9 ksi), worse than 91% of steel grades
- Hard to polish — 45/100, worse than 84% of steel grades
20R properties
Typical room-temperature values for 20R-AR; bars are the position among steel grades.
Physical3
20R 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).
Mechanical16
20R has a yield strength of 275 MPa (39.9 ksi) and a tensile strength of 460 MPa (66.7 ksi) — weaker than 91% of steel grades. Elongation at break is 30% and the elastic modulus is 206 GPa (29.9 Msi).
Thermal6
20R 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
20R conducts electricity at 10.8 % IACS, better than 94% of steel grades.
Chemical & Environmental3
Corrosion resistance is not recommended (12/100), worse than 53% of steel grades.
Sustainability4
Producing a kilogram of 20R takes about 25 MJ of energy and emits 2 kg of CO₂ — less than 82% of steel grades. Typical recycled content is 25%.
Manufacturability6
20R's machinability is good (65/100, better than 93% of steel grades); weldability excellent (95/100); 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. 20R is highlighted; hover a dot for its name, or open the interactive family chart.
Working with 20R
Is 20R easy to machine?
Machines like mild steel at ~65 % of AISI 1212; gummy chips in the as-rolled state, so use positive rake, good chip breakers and generous coolant.
Can 20R be welded?
Excellent weldability with CEV ≈ 0.35 — SMAW/SAW/GMAW with E7018 or F7A2-EM12K class consumables; preheat 100–150 °C above ~40 mm and PWHT at 600–640 °C per GB 150 when required.
Can 20R be formed, bent or molded?
Cold bends to 1.5×t radius; hot forming of heads at 900–1000 °C should be followed by normalizing if the finishing temperature is uncontrolled.
20R 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 713 Q245R ≤0.20 | ≤ 0.2 | 0.17 |
| Si | ≤ 0.35 | 0.25 |
| Mn | 0.5 – 1 | 0.8 |
| P | ≤ 0.03 | 0.02 |
| S≤0.003 for HIC grade | ≤ 0.01 | 0.01 |
| Crresidual | ≤ 0.3 | 0.05 |
| Niresidual | ≤ 0.3 | 0.05 |
| Curesidual | ≤ 0.3 | 0.05 |
| Moresidual | ≤ 0.08 | 0.01 |
| Alsacid-soluble Al, fine-grain practice | ≥ 0.02 | 0.03 |
| Fe | balance |
What surface finishes work on 20R?
No inherent corrosion resistance — shot-blast to Sa2½ and epoxy/zinc-rich prime, or use cladding/weld overlay/internal lining for wet service.
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 20R in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- Similar grades
- A516 Gr 60
How much does 20R cost?
20R 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.
20R — frequently asked
What is 20R used for?
20R is typically used for pressure vessel shells, storage tanks and process vessels. In short: workhorse vessel plate; HIC and Z35 options; best-value weldable plate.
What is the yield strength of 20R?
20R has a typical yield strength of 275 MPa (39.9 ksi) and a tensile strength of 460 MPa (66.7 ksi) — weaker than 91% of steel grades. Strength varies by condition: see the 5 listed tempers.
Is 20R easy to machine?
Reasonably — machinability is rated good (65/100, better than 93% of steel grades). Machines like mild steel at ~65 % of AISI 1212; gummy chips in the as-rolled state, so use positive rake, good chip breakers and generous coolant.
Can 20R be welded?
Yes — weldability is rated excellent (95/100). Excellent weldability with CEV ≈ 0.35 — SMAW/SAW/GMAW with E7018 or F7A2-EM12K class consumables; preheat 100–150 °C above ~40 mm and PWHT at 600–640 °C per GB 150 when required.
What surface finishes work on 20R?
No inherent corrosion resistance — shot-blast to Sa2½ and epoxy/zinc-rich prime, or use cladding/weld overlay/internal lining for wet service.
Can 20R be formed, bent or molded?
Cold bends to 1.5×t radius; hot forming of heads at 900–1000 °C should be followed by normalizing if the finishing temperature is uncontrolled.
What is the maximum service temperature of 20R?
20R 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 20R-AR and 20R TMCP?
AR is the default condition — standard stock condition for thin/medium 20R–Q245R vessel plate where no normalizing is required. TMCP: controlled-rolled plate giving normalized-like fine grain without a separate furnace cycle; good toughness with lower carbon equivalent. Yield strength is 275 MPa in AR versus 290 MPa in TMCP.
How much does 20R cost?
20R 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
- GB 6654 (20R, superseded) (1996)
- ASTM A516/A516M Pressure Vessel Plates, Carbon Steel — ASTM International (2021)
- ASM Handbook Vol.1 Properties and Selection: Irons, Steels — ASM International (1990)
- ASME BPVC Section II Part D — material properties tables — ASME (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.