Steel A656
ASTM A656
ASTM A656 is a hot-rolled high-strength low-alloy (HSLA) structural plate that uses microalloying with vanadium or titanium/niobium plus controlled rolling to reach 345–690 MPa yield across Grades 50, 60, 70, 80 and 100 (Types 3 and 7), while keeping better cold bending than conventional quenched-and-tempered plate.
Values for the HR condition
A656 tempers and conditions
A656 is supplied in 9 conditions, soft to hard. HR is the default FabDigit quotes; the values on this page are for it.
Compare all 9 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Grade 50 | Lowest strength level — pick when formability and weldability outrank weight saving. | 380 | 450 | 24 | 140 HB | — |
Grade 60 | Mid-level HSLA plate for lightly loaded formed structures. | 450 | 520 | 21 | 160 HB | — |
Grade 70 | Step below the popular Gr 80 when a little more bend ductility is needed. | 520 | 590 | 18 | 12 HRC | 9 % IACS |
titanium microalloyed chemistry | Ti-bearing variant with finer grain and slightly better low-temperature notch toughness at the same strength level. | 575 | 650 | 17 | 17 HRC | 9 % IACS |
HRDefault Hot rolled | Standard mill condition for A656 plate — pick for welded structural weight-saving parts up to ~25 mm. | 580 | 660 | 16 | 215 HB | — |
Grade 80 | The workhorse A656 grade for dump bodies, crane booms and trailer structures. | 580 | 660 | 16 | 18 HRC | 9 % IACS |
vanadium microalloyed chemistry | Default chemistry type supplied by most mills; V precipitation strengthening, good weldability. | 580 | 660 | 16 | 18 HRC | 9 % IACS |
Cold rolled | Thin-gauge cold-reduced product for stamped high-strength panels; better surface and tighter gauge, lower ductility than hot-rolled. | 620 | 700 | 12 | 21 HRC | 9 % IACS |
Grade 100 | Highest A656 strength level for maximum payload / minimum plate thickness; tightest forming and welding control. | 720 | 800 | 14 | 25 HRC | — |
Supply forms, finishes and certifications
Ways A656 is supplied — form, process route, surface or paperwork — without a datasheet of their own. The property values above apply.
| Option | What it is | Type |
|---|---|---|
Galvanized | Hot-dip zinc coated A656-class sheet/plate | Coating |
What is A656?
ASTM A656 is a hot-rolled high-strength low-alloy (HSLA) structural plate that uses microalloying with vanadium or titanium/niobium plus controlled rolling to reach 345–690 MPa yield across Grades 50, 60, 70, 80 and 100 (Types 3 and 7), while keeping better cold bending than conventional quenched-and-tempered plate. It is used for weight-sensitive welded structures such as crane booms, dump bodies and truck frames, and is available hot-rolled, cold-rolled and galvanized. Default values are 580 MPa yield, 660 MPa tensile, 16 % elongation, 215 HB and a service ceiling of 350 °C. Corrosion resistance is the same as plain carbon steel (score 12), heat input and preheat must be controlled on thick plate and Gr 80/100, and elongation falls as strength rises. A656 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). A656 has a yield strength of 580 MPa (84.1 ksi) and a tensile strength of 660 MPa (95.7 ksi) — stronger than 75% of steel grades. Elongation at break is 16% and the elastic modulus is 200 GPa (29 Msi).
What is A656 used for?
- Crane booms
- Truck and trailer frames
- Dump truck bodies
- Hoppers and material-handling chutes
- Agricultural machinery structures
- Lifting and support beams
Advantages
- Forms and bends easily — 65/100, better than 81% of steel grades
- Readily welded — 75/100, better than 76% of steel grades
- High strength — 580 MPa (84.1 ksi), better than 75% of steel grades
Limitations
- Hard to polish — 45/100, worse than 84% of steel grades
A656 properties
Typical room-temperature values for A656-HR; bars are the position among steel grades.
Physical3
A656 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).
Mechanical17
A656 has a yield strength of 580 MPa (84.1 ksi) and a tensile strength of 660 MPa (95.7 ksi) — stronger than 75% of steel grades. Elongation at break is 16% and the elastic modulus is 200 GPa (29 Msi).
Thermal6
A656 is rated for continuous service to 350°C (662 °F). It conducts heat at 46 W/m·K (26.6 BTU/hr·ft·°F), better than 71% of steel grades. Thermal expansion is 12 µm/m·K (6.67 µin/in·°F).
Electrical3
A656 conducts electricity at 9 % IACS, better than 71% of steel grades.
Chemical & Environmental3
Corrosion resistance is not recommended (12/100), worse than 53% of steel grades.
Sustainability4
Producing a kilogram of A656 takes about 25 MJ of energy and emits 2 kg of CO₂ — less than 82% of steel grades. Typical recycled content is 30%.
Manufacturability7
A656's machinability is fair (50/100, worse than 53% of steel grades); weldability very good (75/100); formability good (65/100).
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. A656 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with A656
Is A656 easy to machine?
Machines like a 200–250 HB low-alloy steel — rigid setups, coated carbide, moderate speeds; drilling and plasma/laser cutting are routine but expect edge hardening on thermally cut faces.
Can A656 be welded?
Good weldability at CE < 0.45 — use low-hydrogen (E70xx–E80xx / matching flux-cored) consumables, control heat input and preheat 100–150 °C for Gr 80/100 or thicknesses over ~20 mm.
Can A656 be formed, bent or molded?
Designed for cold bending: bend transverse to rolling direction, use generous radii (≈3–4t for Gr 80, 4–5t for Gr 100) and allow for high springback.
Manufacturability
The process limits FabDigit applies to A656. Every A656 part is priced by an engineer; design inside these and the quote comes back without a redesign loop.
CNC machining
| Machinability | Good50 / 100 |
|---|---|
| ISO material group | P.2 |
| Cutting speed (rough / finish) | 180 / 210 m/min |
| Minimum wall | 0.8 mm |
| Minimum internal radius | 1 mm |
| Drill depth limit | 5× diameter |
| Best surface (machined / polished) | Ra 1.6 / — |
| Hardenable after machining | No |
Sheet metal
| Formability | Better65 / 100 |
|---|---|
| Weldability | Better75 / 100 |
| Bendable | Yes |
A656 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 |
|---|---|---|
| Cheat analysis maximum | ≤ 0.18 | 0.1 |
| Mn | ≤ 1.65 | 1.4 |
| Si | ≤ 0.6 | 0.3 |
| P | ≤ 0.03 | 0.01 |
| Slower S usual for Gr 80/100 with improved formability | ≤ 0.04 | 0.01 |
| VType 3 (vanadium) chemistry | 0.05 – 0.15 | 0.08 |
| TiType 7 (titanium) chemistry | ≤ 0.1 | 0.03 |
| Nboptional microalloy addition | ≤ 0.1 | |
| Alfine-grain practice / deoxidation | ≥ 0.02 | 0.03 |
| N | ≤ 0.02 | 0.01 |
| Fe | balance |
What surface finishes work on A656?
No inherent corrosion resistance — shot blast to SA 2.5 then zinc-rich primer/paint, hot-dip galvanize, or metallize; not anodizable.
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).
Plating
CVD Coating
Black / Phosphate
Thermal Spray
How much does A656 cost?
A656 is a budget-cost steel ($), cheaper than about 98% 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.
A656 — frequently asked
What is A656 used for?
A656 is typically used for crane booms, truck and trailer frames, dump truck bodies, hoppers and material-handling chutes, agricultural machinery structures and lifting and support beams. In short: high-strength low-alloy structural.
What is the yield strength of A656?
A656 has a typical yield strength of 580 MPa (84.1 ksi) and a tensile strength of 660 MPa (95.7 ksi) — stronger than 75% of steel grades. Strength varies by condition: see the 9 listed tempers.
Is A656 easy to machine?
Reasonably — machinability is rated fair (50/100, worse than 53% of steel grades). Machines like a 200–250 HB low-alloy steel — rigid setups, coated carbide, moderate speeds; drilling and plasma/laser cutting are routine but expect edge hardening on thermally cut faces.
Can A656 be welded?
Yes — weldability is rated very good (75/100). Good weldability at CE < 0.45 — use low-hydrogen (E70xx–E80xx / matching flux-cored) consumables, control heat input and preheat 100–150 °C for Gr 80/100 or thicknesses over ~20 mm.
What surface finishes work on A656?
No inherent corrosion resistance — shot blast to SA 2.5 then zinc-rich primer/paint, hot-dip galvanize, or metallize; not anodizable.
Can A656 be formed, bent or molded?
Designed for cold bending: bend transverse to rolling direction, use generous radii (≈3–4t for Gr 80, 4–5t for Gr 100) and allow for high springback.
What is the maximum service temperature of A656?
A656 is rated for continuous use to about 350°C (662 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between A656-HR and A656-Gr50?
HR is the default condition — standard mill condition for A656 plate — pick for welded structural weight-saving parts up to ~25 mm. Gr50: lowest strength level — pick when formability and weldability outrank weight saving. Yield strength is 580 MPa in HR versus 380 MPa in Gr50.
How much does A656 cost?
A656 is a budget-cost steel ($), cheaper than about 98% 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.
Can FabDigit make parts in A656?
Yes — A656 is available for CNC machining and sheet metal; every part is priced by an engineer rather than instantly. Upload a STEP file to get a price and a DFM check.
Sources
- ASTM A656/A656M — Hot-Rolled Structural Steel, HSLA Plate with Improved Formability — ASTM International (2018)
- 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)
- HSLA structural plate (A656 Gr 80) product data — Nucor / SSAB service-center literature (2023)
- GB/T 16270 (comparison grades Q550/Q690) — SAC (2009)
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.