Steel A204 · supply condition · default condition
Steel A204-HR
Properties of the HR condition, compared with the other A204 tempers.
Standard stocked condition for thinner A204 plate where as-rolled properties meet the grade minima.
What is A204-HR?
A204-HR is A204 supplied in the HR condition — standard stocked condition for thinner A204 plate where as-rolled properties meet the grade minima. A204-HR has a yield strength of 315 MPa (45.7 ksi) and a tensile strength of 520 MPa (75.4 ksi) — weaker than 82% of steel grades. Elongation at break is 24% and the elastic modulus is 205 GPa (29.7 Msi). A204-HR 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).
Advantages
- High service temperature — 480°C (896 °F), better than 88% of steel grades
Limitations
- Low strength — 315 MPa (45.7 ksi), worse than 82% of steel grades
A204-HR properties
Typical room-temperature values for A204-HR — 7 properties are specific to this condition; the rest are grade-level values shared by every A204 temper. Each bar shows where the value sits among the steel grades in FabDigit's library — further right is higher.
Physical3
A204-HR 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).
Mechanical14
A204-HR has a yield strength of 315 MPa (45.7 ksi) and a tensile strength of 520 MPa (75.4 ksi) — weaker than 82% of steel grades. Elongation at break is 24% and the elastic modulus is 205 GPa (29.7 Msi).
Thermal6
A204-HR is rated for continuous service to 480°C (896 °F). It conducts heat at 44 W/m·K (25.4 BTU/hr·ft·°F), better than 57% of steel grades. Thermal expansion is 12.3 µm/m·K (6.83 µin/in·°F).
Electrical3
A204-HR conducts electricity at 8.2 % IACS, better than 60% of steel grades.
Chemical & Environmental3
Corrosion resistance is not recommended (12/100), worse than 53% of steel grades.
Sustainability4
Producing a kilogram of A204-HR takes about 26 MJ of energy and emits 2 kg of CO₂ — less than 64% of steel grades. Typical recycled content is 25%.
Manufacturability8
A204-HR's machinability is good (58/100, better than 75% of steel grades); weldability very good (70/100); formability good (60/100).
Common Calculations5
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
Other A204 tempers and conditions
A204 is also supplied in 7 other conditions. The full side-by-side table is on the A204 overview.
- HRDefaultStandard stocked condition for thinner A204 plate where as-rolled properties meet the grade minima.315 MPa yield · 160 HB
- Q&TUsed for thick sections or when the upper end of the tensile range plus high toughness is required.405 MPa yield · 180 HB
- Gr.CUse where the thinnest possible shell is wanted; slightly higher carbon so welding controls are stricter.340 MPa yield · 163 HB
- Gr.BMost widely stocked A204 grade; default choice for boiler drums and elevated-temperature vessels.315 MPa yield · 152 HB
- Gr.AChoose Grade A when maximum weldability and ductility matter more than allowable stress.290 MPa yield · 140 HB
Working with A204-HR
Is A204 easy to machine?
Machines like a 190 HB low-alloy steel — carbide tooling, moderate speeds, good chip control; slightly gummier than plain carbon steel due to Mo.
Can A204 be welded?
Readily welded with matching 0.5Mo consumables (E7018-A1 / ER80S-D2); preheat ~100–150 °C on thick plate and apply PWHT at 620–680 °C per code.
Can A204 be formed, bent or molded?
Cold-form only mild radii; hot form heads at 900–1000 °C and re-normalize afterwards to restore properties.
What surface finishes work on A204?
Blast and paint, phosphate or metallize; no anodizing — for corrosive service use stainless weld overlay or roll-bonded clad plate.
A204 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 |
|---|---|---|
| CGr.A ≤0.25, Gr.B ≤0.27, Gr.C ≤0.28 (thickness dependent) | ≤ 0.27 | 0.2 |
| Mnheat analysis max; Gr.C to 0.90 | ≤ 0.9 | 0.7 |
| P | ≤ 0.04 | 0.02 |
| S | ≤ 0.04 | 0.01 |
| Si | 0.15 – 0.4 | 0.25 |
| Mocreep-strengthening addition | 0.45 – 0.6 | 0.5 |
| Fe | balance | — |
A204-HR — frequently asked
What is A204-HR used for?
A204-HR is typically used for boilers, storage tanks and refinery vessels. In short: molybdenum pressure plate.
What is the yield strength of A204-HR?
A204-HR has a typical yield strength of 315 MPa (45.7 ksi) and a tensile strength of 520 MPa (75.4 ksi) — weaker than 82% of steel grades. Strength varies by condition: see the 8 listed tempers.
Is A204-HR easy to machine?
Reasonably — machinability is rated good (58/100, better than 75% of steel grades). Machines like a 190 HB low-alloy steel — carbide tooling, moderate speeds, good chip control; slightly gummier than plain carbon steel due to Mo.
Can A204-HR be welded?
Yes — weldability is rated very good (70/100). Readily welded with matching 0.5Mo consumables (E7018-A1 / ER80S-D2); preheat ~100–150 °C on thick plate and apply PWHT at 620–680 °C per code.
What surface finishes work on A204-HR?
Blast and paint, phosphate or metallize; no anodizing — for corrosive service use stainless weld overlay or roll-bonded clad plate.
Can A204-HR be formed, bent or molded?
Cold-form only mild radii; hot form heads at 900–1000 °C and re-normalize afterwards to restore properties.
What is the maximum service temperature of A204-HR?
A204-HR is rated for continuous use to about 480°C (896 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
Can FabDigit make parts in A204-HR?
Yes — A204-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
- ASTM A204/A204M — Pressure Vessel Plates, Alloy Steel, Molybdenum — ASTM International (2019)
- ASME BPVC Section II Part A (SA-204) and Part D (allowable stresses, physical properties) — ASME (2023)
- EN 10028-2 (16Mo3) — Flat products for pressure purposes, creep-resisting steels — CEN (2017)
- ASM Handbook Vol.1 — Properties and Selection: Irons, Steels and High-Performance Alloys — ASM International (1990)
- ASM Handbook Vol.13C / Vol.19 — Corrosion and Fatigue of steels — ASM International (2006)
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.