Steel A516 Gr 70 · heat-treated state
Steel A516 Gr 70 Q&T
Properties of the Q&T condition, compared with the other A516 Gr 70 tempers.
Ordered for thick plate where the highest yield strength and lowest transition temperature within the grade are wanted; requires careful PWHT control of welds.
What is A516 Gr 70 Q&T?
A516 Gr 70 Q&T is A516 Gr 70 heat treated to Q&T — ordered for thick plate where the highest yield strength and lowest transition temperature within the grade are wanted; requires careful PWHT control of welds. A516 Gr 70 Q&T has a yield strength of 400 MPa (58 ksi) and a tensile strength of 590 MPa (85.6 ksi) — weaker than 60% of steel grades. Elongation at break is 24% and the elastic modulus is 200 GPa (29 Msi). A516 Gr 70 Q&T 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; Q&T is available on request or by drawing note.
Advantages
- Tough — resists crack growth — 180 MPa·√m (163.8 ksi·√in), better than 99% of steel grades
- Conducts heat well — 52 W/m·K (30 BTU/hr·ft·°F), better than 98% of steel grades
- Readily welded — 85/100, better than 83% of steel grades
- High electrical conductivity — 10 % IACS, better than 82% of steel grades
- Forms and bends easily — 66/100, better than 82% of steel grades
Limitations
- Hard to polish — 45/100, worse than 84% of steel grades
A516 Gr 70 Q&T properties
Typical room-temperature values for A516 Gr 70 Q&T — 16 properties are specific to this condition; the rest are grade-level values shared by every A516 Gr 70 temper. Each bar shows where the value sits among the steel grades in FabDigit's library — further right is higher.
Physical3
A516 Gr 70 Q&T 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
A516 Gr 70 Q&T has a yield strength of 400 MPa (58 ksi) and a tensile strength of 590 MPa (85.6 ksi) — weaker than 60% of steel grades. Elongation at break is 24% and the elastic modulus is 200 GPa (29 Msi).
Thermal6
A516 Gr 70 Q&T is rated for continuous service to 400°C (752 °F). It conducts heat at 52 W/m·K (30 BTU/hr·ft·°F), better than 98% of steel grades. Thermal expansion is 12 µm/m·K (6.67 µin/in·°F).
Electrical3
A516 Gr 70 Q&T conducts electricity at 10 % IACS, better than 82% of steel grades.
Chemical & Environmental3
Corrosion resistance is not recommended (12/100), worse than 53% of steel grades.
Sustainability4
Producing a kilogram of A516 Gr 70 Q&T takes about 25 MJ of energy and emits 2.1 kg of CO₂ — less than 82% of steel grades. Typical recycled content is 30%.
Manufacturability7
A516 Gr 70 Q&T's machinability is good (55/100, better than 62% of steel grades); weldability excellent (85/100); formability good (66/100).
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
Other A516 Gr 70 tempers and conditions
A516 Gr 70 is also supplied in 5 other conditions. The full side-by-side table is on the A516 Gr 70 overview.
- HRDefaultDefault stock condition for plate up to ~40 mm in ambient-service vessels and tanks where no low-temperature impact requirement applies.320 MPa yield · 150 HB
- Q&TOrdered for thick plate where the highest yield strength and lowest transition temperature within the grade are wanted; requires careful PWHT control of welds.400 MPa yield · 180 HB
- NormalizedStandard requirement for plate over ~40 mm and for low-temperature Charpy qualification (typically to -45 °C); refines grain and raises toughness uniformity.315 MPa yield · 146 HB
- N&TPick for heavy-wall vessels needing both refined grain and stress-relieved, dimensionally stable plate with high, consistent Charpy energies.310 MPa yield · 143 HB
- SROrdered when the plate must be tested in the simulated post-weld-heat-treated condition or when residual stress from forming must be removed before machining.300 MPa yield · 145 HB
- AnnealedChoose when severe cold forming, deep flanging or minimum hardness for machining of thick plate is needed; gives the lowest strength of the family.290 MPa yield · 140 HB
Working with A516 Gr 70 Q&T
Is A516 Gr 70 easy to machine?
Machines like 0.2–0.3 %C plate at ~65 % of AISI 1212; free-machining is limited by low sulfur in HIC grades, so use positive-rake carbide, generous coolant and expect gummy chips in annealed plate.
Can A516 Gr 70 be welded?
Excellent weldability (ASME P-No.1 Gr.2) with SMAW E7018 / SAW EM12K-F7; preheat 50–150 °C for thick sections and PWHT at 595–650 °C above ~38 mm or where code requires.
Can A516 Gr 70 be formed, bent or molded?
Readily cold-rolled into shells and cold-flanged (min bend radius ≈2t); hot forming 900–1000 °C followed by re-normalizing when the plate was ordered normalized.
What surface finishes work on A516 Gr 70?
No anodizing; shot-blast to SA 2.5 then epoxy/zinc-rich primer, hot-dip galvanize, or weld-overlay/roll-bond clad with 308L/Inconel for corrosive duty.
A516 Gr 70 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 |
|---|---|---|
| C0.27 max ≤12.5 mm; 0.28/0.30/0.31 max for heavier thickness ranges per ASTM A516 | ≤ 0.31 | 0.22 |
| Mn0.85–1.20 for ≤12.5 mm; 0.85–1.20/0.79–1.30 heat vs product analysis | 0.79 – 1.3 | 1.05 |
| Si0.15–0.40 heat analysis (silicon-killed) | 0.13 – 0.45 | 0.25 |
| P | ≤ 0.04 | 0.02 |
| S≤0.002–0.005 typical for HIC/NACE service | ≤ 0.04 | 0.01 |
| Fe | balance | — |
A516 Gr 70 Q&T — frequently asked
What is A516 Gr 70 Q&T used for?
A516 Gr 70 Q&T is typically used for boilers, pressure vessels and storage tanks. In short: pressure-vessel quality plate.
What is the yield strength of A516 Gr 70 Q&T?
A516 Gr 70 Q&T has a typical yield strength of 400 MPa (58 ksi) and a tensile strength of 590 MPa (85.6 ksi) — weaker than 60% of steel grades. Strength varies by condition: see the 6 listed tempers.
Is A516 Gr 70 Q&T easy to machine?
Reasonably — machinability is rated good (55/100, better than 62% of steel grades). Machines like 0.2–0.3 %C plate at ~65 % of AISI 1212; free-machining is limited by low sulfur in HIC grades, so use positive-rake carbide, generous coolant and expect gummy chips in annealed plate.
Can A516 Gr 70 Q&T be welded?
Yes — weldability is rated excellent (85/100). Excellent weldability (ASME P-No.1 Gr.2) with SMAW E7018 / SAW EM12K-F7; preheat 50–150 °C for thick sections and PWHT at 595–650 °C above ~38 mm or where code requires.
What surface finishes work on A516 Gr 70 Q&T?
No anodizing; shot-blast to SA 2.5 then epoxy/zinc-rich primer, hot-dip galvanize, or weld-overlay/roll-bond clad with 308L/Inconel for corrosive duty.
Can A516 Gr 70 Q&T be formed, bent or molded?
Readily cold-rolled into shells and cold-flanged (min bend radius ≈2t); hot forming 900–1000 °C followed by re-normalizing when the plate was ordered normalized.
What is the maximum service temperature of A516 Gr 70 Q&T?
A516 Gr 70 Q&T 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 A516 Gr 70-HR and A516 Gr 70-SR?
HR is the default condition — default stock condition for plate up to ~40 mm in ambient-service vessels and tanks where no low-temperature impact requirement applies. SR: ordered when the plate must be tested in the simulated post-weld-heat-treated condition or when residual stress from forming must be removed before machining. Yield strength is 320 MPa in HR versus 300 MPa in SR.
Can FabDigit make parts in A516 Gr 70 Q&T?
Yes — A516 Gr 70 Q&T 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 A516/A516M — Pressure Vessel Plates, Carbon Steel, for Moderate- and Lower-Temperature Service — ASTM International (2021)
- ASME BPVC Section II Part A (SA-516) and Part D (allowable stresses, physical properties) — ASME (2023)
- ASME BPVC Section VIII Div.1 UCS-66 impact test exemption curves — ASME (2023)
- ASM Handbook Vol.1 — Properties and Selection: Irons, Steels and High-Performance Alloys — ASM International (1990)
- ASM Handbook Vol.19 — Fatigue and Fracture — ASM International (1996)
- GB/T 713 Q245R/Q345R — SAC (2014)
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.