Steel A517 Grade B
ASTM A517 Grade B
A517 Grade B is a chromium-molybdenum-boron quenched-and-tempered pressure-vessel plate with 100 ksi minimum yield.
Reference datasheet — A517 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 QT condition
A517 Grade B tempers and conditions
A517 Grade B is supplied in 3 conditions, soft to hard. QT is the default FabDigit quotes; the values on this page are for it.
Compare all 3 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Q&T heavy section | Choose for thick-wall vessels and heavy structures; reduced strength minima reflect lower quench severity through thickness. | 690 | 800 | 18 | 22 HRC | — |
Q&T + PWHT/stress relieved | Required when the fabricated vessel must be post-weld heat treated; expect a modest loss of yield and tensile strength. | 710 | 815 | 19 | 22 HRC | 7.2 % IACS |
QTDefault Quenched and tempered | Standard as-supplied condition for pressure vessel and high-strength structural plate up to 65 mm thick. | 760 | 860 | 18 | 24 HRC | — |
What is A517 Grade B?
A517 Grade B is a chromium-molybdenum-boron quenched-and-tempered pressure-vessel plate with 100 ksi minimum yield. Fabricators use it where wall thickness and weight must drop in high-pressure service; QT plate runs about 760 MPa yield, 860 MPa tensile, 18 % elongation and 255 HB (24 HRC), with service to 370 °C. Weldability is moderate (score 55) and formability limited (40), so joints require low-hydrogen 100 ksi consumables, preheat and controlled heat input, and bends need generous radii. A514 Grade B is the structural equivalent where no vessel code applies. A517 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). A517 Grade B has a yield strength of 760 MPa (110 ksi) and a tensile strength of 860 MPa (125 ksi) — stronger than 85% of steel grades. Elongation at break is 18% and the elastic modulus is 205 GPa (29.7 Msi).
What is A517 Grade B used for?
- pressure vessels
- boiler drums
- heavy pipe fittings
Advantages
- Tough — resists crack growth — 130 MPa·√m (118.3 ksi·√in), better than 89% of steel grades
- High strength — 760 MPa (110 ksi), better than 85% of steel grades
Limitations
- Difficult to machine — 38/100, worse than 80% of steel grades
A517 Grade B properties
Typical room-temperature values for A517 Grade B-QT; bars are the position among steel grades.
Physical3
A517 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
A517 Grade B has a yield strength of 760 MPa (110 ksi) and a tensile strength of 860 MPa (125 ksi) — stronger than 85% of steel grades. Elongation at break is 18% and the elastic modulus is 205 GPa (29.7 Msi).
Thermal6
A517 Grade B is rated for continuous service to 370°C (698 °F). It conducts heat at 42 W/m·K (24.3 BTU/hr·ft·°F), worse than 56% of steel grades. Thermal expansion is 12 µm/m·K (6.67 µin/in·°F).
Electrical2
A517 Grade B has an electrical resistivity of 2.4×10⁻⁷ Ω·m.
Chemical & Environmental3
Corrosion resistance is not recommended (13/100), better than 66% of steel grades.
Sustainability4
Producing a kilogram of A517 Grade B takes about 30 MJ of energy and emits 2.3 kg of CO₂ — more than 56% of steel grades. Typical recycled content is 25%.
Manufacturability7
A517 Grade B's machinability is fair (38/100, worse than 80% of steel grades); weldability good (55/100); formability fair (40/100).
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. A517 Grade B is highlighted; hover a dot for its name, or open the interactive family chart.
Working with A517 Grade B
Is A517 Grade B easy to machine?
Machines like a 250 HB Q&T alloy steel — rigid setups, carbide tooling, moderate speeds; avoid heavy grinding burn that re-hardens the surface.
Can A517 Grade B be welded?
Weld with low-hydrogen 100 ksi-class consumables (E11018-M / ER110S-1), preheat typically 65–150 °C by thickness, and cap heat input to protect the HAZ toughness.
Can A517 Grade B be formed, bent or molded?
Cold bend only at generous radii (≈3–4t or more) with the bend line across the rolling direction; hot forming above the tempering temperature destroys the Q&T properties and requires re-heat-treatment.
A517 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 |
|---|---|---|
| C | 0.15 – 0.21 | 0.18 |
| Mn | 0.7 – 1 | 0.85 |
| Si | 0.2 – 0.35 | 0.28 |
| P | ≤ 0.04 | |
| S | ≤ 0.04 | |
| Cr | 0.4 – 0.65 | 0.52 |
| Mo | 0.15 – 0.25 | 0.2 |
| V | 0.03 – 0.08 | 0.05 |
| Tigrain refinement / boron protection | 0.01 – 0.03 | 0.02 |
| Bhardenability booster | 5×10⁻⁴ – 0.01 | 0 |
| Fe | balance |
What surface finishes work on A517 Grade B?
Not anodizable — protect by shot-blast plus epoxy/zinc-rich paint or metallizing; use caution with hot-dip galvanizing on high-strength plate due to embrittlement risk.
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
How much does A517 Grade B cost?
A517 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.
A517 Grade B — frequently asked
What is A517 Grade B used for?
A517 Grade B is typically used for pressure vessels, boiler drums and heavy pipe fittings. In short: pressure-vessel T-1 plate; 100 ksi yield vessel steel; cr-Mo-B quenched plate.
What is the yield strength of A517 Grade B?
A517 Grade B has a typical yield strength of 760 MPa (110 ksi) and a tensile strength of 860 MPa (125 ksi) — stronger than 85% of steel grades. Strength varies by condition: see the 3 listed tempers.
Is A517 Grade B easy to machine?
Not especially — machinability is rated fair (38/100, worse than 80% of steel grades). Machines like a 250 HB Q&T alloy steel — rigid setups, carbide tooling, moderate speeds; avoid heavy grinding burn that re-hardens the surface.
Can A517 Grade B be welded?
Yes — weldability is rated good (55/100). Weld with low-hydrogen 100 ksi-class consumables (E11018-M / ER110S-1), preheat typically 65–150 °C by thickness, and cap heat input to protect the HAZ toughness.
What surface finishes work on A517 Grade B?
Not anodizable — protect by shot-blast plus epoxy/zinc-rich paint or metallizing; use caution with hot-dip galvanizing on high-strength plate due to embrittlement risk.
Can A517 Grade B be formed, bent or molded?
Cold bend only at generous radii (≈3–4t or more) with the bend line across the rolling direction; hot forming above the tempering temperature destroys the Q&T properties and requires re-heat-treatment.
What is the maximum service temperature of A517 Grade B?
A517 Grade B is rated for continuous use to about 370°C (698 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between A517 Grade B-QT and A517 Grade B QT-HS?
QT is the default condition — standard as-supplied condition for pressure vessel and high-strength structural plate up to 65 mm thick. QT-HS: choose for thick-wall vessels and heavy structures; reduced strength minima reflect lower quench severity through thickness. Yield strength is 760 MPa in QT versus 690 MPa in QT-HS.
How much does A517 Grade B cost?
A517 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 A517/A517M — Pressure Vessel Plates, Alloy Steel, High-Strength, Quenched and Tempered — ASTM International (2023)
- ASTM A514/A514M — High-Yield-Strength, Quenched and Tempered Alloy Steel Plate — ASTM International (2023)
- ASME BPVC Section II Part D — Material Properties — 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)
- Constructional alloy plate (T-1 type A/B) technical bulletin — steel plate producer (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.