Steel A572 Gr 50 · temper
Steel A572 Gr 50 Annealed
Properties of the Annealed condition, compared with the other A572 Gr 50 tempers.
Use when maximum ductility and lowest hardness are needed for deep forming or heavy machining; yield falls below the 345 MPa structural minimum.
What is A572 Gr 50 Annealed?
A572 Gr 50 Annealed is A572 Gr 50 in the Annealed temper — use when maximum ductility and lowest hardness are needed for deep forming or heavy machining; yield falls below the 345 MPa structural minimum. A572 Gr 50 Annealed has a yield strength of 300 MPa (43.5 ksi) and a tensile strength of 450 MPa (65.3 ksi) — weaker than 86% of steel grades. Elongation at break is 30% and the elastic modulus is 200 GPa (29 Msi). A572 Gr 50 Annealed 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). HR is the default condition FabDigit quotes; Annealed is available on request or by drawing note.
Advantages
- Easy to machine — 65/100, better than 93% of steel grades
- Ductile — tolerates forming and impact — 30%, better than 92% 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 88% 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
A572 Gr 50 Annealed properties
Typical room-temperature values for A572 Gr 50 Annealed — 10 properties are specific to this condition; the rest are grade-level values shared by every A572 Gr 50 temper. Each bar shows where the value sits among the steel grades in FabDigit's library — further right is higher.
Physical3
A572 Gr 50 Annealed 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).
Mechanical15
A572 Gr 50 Annealed has a yield strength of 300 MPa (43.5 ksi) and a tensile strength of 450 MPa (65.3 ksi) — weaker than 86% of steel grades. Elongation at break is 30% and the elastic modulus is 200 GPa (29 Msi).
Thermal6
A572 Gr 50 Annealed is rated for continuous service to 400°C (752 °F). It conducts heat at 50 W/m·K (28.9 BTU/hr·ft·°F), better than 88% of steel grades. Thermal expansion is 11.7 µm/m·K (6.5 µin/in·°F).
Electrical3
A572 Gr 50 Annealed conducts electricity at 8.6 % IACS, better than 66% of steel grades.
Chemical & Environmental3
Corrosion resistance is not recommended (12/100), worse than 53% of steel grades.
Sustainability4
Producing a kilogram of A572 Gr 50 Annealed takes about 25 MJ of energy and emits 1.9 kg of CO₂ — less than 82% of steel grades. Typical recycled content is 40%.
Manufacturability7
A572 Gr 50 Annealed's machinability is good (65/100, better than 93% of steel grades); weldability excellent (85/100); formability very good (75/100).
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
Other A572 Gr 50 tempers and conditions
A572 Gr 50 is also supplied in 4 other conditions. The full side-by-side table is on the A572 Gr 50 overview.
- HRDefaultDefault mill condition for A572 Gr 50 plate, structural shapes and HSS-type sections; meets 345 MPa min yield as-rolled.380 MPa yield · 150 HB
- CDChoose for dimensionally accurate bar stock, machined shafts and pins where the higher yield from drawing is a bonus; residual stress may cause distortion on machining.470 MPa yield · 175 HB
- CRThin sheet/strip form with better flatness and surface finish; strength raised and ductility reduced by cold reduction.450 MPa yield · 170 HB
- NormalizedPick for thick plate or low-temperature service where uniform fine grain and higher Charpy energy are required.370 MPa yield · 150 HB
- AnnealedUse when maximum ductility and lowest hardness are needed for deep forming or heavy machining; yield falls below the 345 MPa structural minimum.300 MPa yield · 130 HB
Working with A572 Gr 50 Annealed
Is A572 Gr 50 easy to machine?
Machines like a 1020–1025 carbon steel at ~58 % of 1212; use rigid setups and positive-rake carbide, expect gummy chips and moderate built-up edge without a free-machining sulfur addition.
Can A572 Gr 50 be welded?
Prequalified in AWS D1.1 (Group II); weld with E70XX/ER70S-6 or matching 480 MPa consumables, preheat 10–110 °C depending on thickness and CE, and avoid excessive heat input to keep HAZ toughness.
Can A572 Gr 50 be formed, bent or molded?
Cold bends readily but needs larger bend radii and more press tonnage than A36 (springback higher); hot forming above ~650 °C on V/Nb grades can coarsen grain and lose the microalloy strengthening.
What surface finishes work on A572 Gr 50?
No natural corrosion resistance — specify shot blast to SA 2.5 plus zinc-rich or epoxy primer, hot-dip galvanizing (watch Si level for coating thickness), or metallizing; anodizing is not applicable.
A572 Gr 50 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 |
|---|---|---|
| C0.23 max for Gr 50; often ≤0.20 for good weldability | ≤ 0.23 | 0.18 |
| Mn1.35 max (plate/shapes); 1.65 max allowed for some Gr 60/65 forms | ≤ 1.35 | 1.15 |
| P | ≤ 0.04 | 0.02 |
| S | ≤ 0.05 | 0.02 |
| Si0.40 max for plate/bar; 0.15–0.40 for some shapes | ≤ 0.4 | 0.25 |
| NbType 1 microalloying (columbium) | 0.01 – 0.05 | 0.03 |
| VType 2 microalloying; Type 3 = Nb + V combined | 0.01 – 0.15 | 0.05 |
| TiType 5 (titanium) option | ≤ 0.05 | 0.02 |
| NV:N ratio ≥ 4:1 when nitrogen intentionally added | ≤ 0.02 | 0.01 |
| Fe | balance | — |
A572 Gr 50 Annealed — frequently asked
What is A572 Gr 50 Annealed used for?
A572 Gr 50 Annealed is typically used for bridges, crane structures and building frames. In short: workhorse HSLA plate.
What is the yield strength of A572 Gr 50 Annealed?
A572 Gr 50 Annealed has a typical yield strength of 300 MPa (43.5 ksi) and a tensile strength of 450 MPa (65.3 ksi) — weaker than 86% of steel grades. Strength varies by condition: see the 5 listed tempers.
Is A572 Gr 50 Annealed easy to machine?
Reasonably — machinability is rated good (65/100, better than 93% of steel grades). Machines like a 1020–1025 carbon steel at ~58 % of 1212; use rigid setups and positive-rake carbide, expect gummy chips and moderate built-up edge without a free-machining sulfur addition.
Can A572 Gr 50 Annealed be welded?
Yes — weldability is rated excellent (85/100). Prequalified in AWS D1.1 (Group II); weld with E70XX/ER70S-6 or matching 480 MPa consumables, preheat 10–110 °C depending on thickness and CE, and avoid excessive heat input to keep HAZ toughness.
What surface finishes work on A572 Gr 50 Annealed?
No natural corrosion resistance — specify shot blast to SA 2.5 plus zinc-rich or epoxy primer, hot-dip galvanizing (watch Si level for coating thickness), or metallizing; anodizing is not applicable.
Can A572 Gr 50 Annealed be formed, bent or molded?
Cold bends readily but needs larger bend radii and more press tonnage than A36 (springback higher); hot forming above ~650 °C on V/Nb grades can coarsen grain and lose the microalloy strengthening.
What is the maximum service temperature of A572 Gr 50 Annealed?
A572 Gr 50 Annealed is rated for continuous use to about 400°C (752 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between A572 Gr 50-HR and A572 Gr 50-CD?
HR is the default condition — default mill condition for A572 Gr 50 plate, structural shapes and HSS-type sections; meets 345 MPa min yield as-rolled. CD: choose for dimensionally accurate bar stock, machined shafts and pins where the higher yield from drawing is a bonus; residual stress may cause distortion on machining. Yield strength is 380 MPa in HR versus 470 MPa in CD.
Can FabDigit make parts in A572 Gr 50 Annealed?
Yes — A572 Gr 50 Annealed 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 A572/A572M — High-Strength Low-Alloy Columbium-Vanadium Structural Steel — ASTM International (2021)
- ASTM A6/A6M — General Requirements for Rolled Structural Steel Bars, Plates, Shapes and Sheet Piling — ASTM International (2019)
- AWS D1.1/D1.1M Structural Welding Code — Steel — American Welding Society (2020)
- ASM Handbook Vol.1 — Properties and Selection: Irons, Steels, and High-Performance Alloys — ASM International (1990)
- Steel Construction Manual, 15th ed. — AISC (2017)
- GB/T 1591 (Q345/Q355 comparison grade) — SAC (2018)
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.