Steel Q460
GB Q460
Q460 is a micro-alloyed high-strength low-alloy structural steel from the Chinese GB/T 1591 family, using Nb/V/Ti additions with normalizing, TMCP or quench-and-temper processing to reach a 460 MPa yield class; close counterparts are S460N and SM570.
Values for the HR condition
Q460 tempers and conditions
Q460 is supplied in 6 conditions, soft to hard. HR is the default FabDigit quotes; the values on this page are for it.
Compare all 6 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
HRDefault Hot rolled | Standard stocked condition for plate, sections and coil where service temperature stays at or above 0 °C. | 500 | 620 | 21 | 185 HB | 8.2 % IACS |
Weathering (atmospheric corrosion resistant) steel Q460NH, GB/T 4171 | Pick for unpainted or long-maintenance-interval exposed structures where the Cu-Cr-Ni patina roughly doubles-to-quadruples paint-free life. | 500 | 620 | 20 | 190 HB | 7.6 % IACS |
Normalized | Pick when guaranteed low-temperature notch toughness down to −40/−60 °C and uniform through-thickness properties are required. | 505 | 630 | 22 | 185 HB | 8.2 % IACS |
Building structural steel plate | Pick for seismic building frames: capped yield range and yield/tensile ratio ≤0.83 plus through-thickness (Z-direction) options. | 505 | 630 | 22 | 188 HB | 8.2 % IACS |
Bridge structural steel | Pick for welded steel bridges needing certified −40 °C impact energy, fine-grain practice and tight flatness/ultrasonic quality. | 505 | 630 | 22 | 187 HB | 8.2 % IACS |
Thermomechanically controlled processed | Pick for the leanest carbon equivalent and best field weldability with low-temperature toughness, typically in thick plate. | 510 | 610 | 23 | 180 HB | — |
What is Q460?
Q460 is a micro-alloyed high-strength low-alloy structural steel from the Chinese GB/T 1591 family, using Nb/V/Ti additions with normalizing, TMCP or quench-and-temper processing to reach a 460 MPa yield class; close counterparts are S460N and SM570. Typical supplied values are 500 MPa yield, 620 MPa tensile and 21 % elongation at about 185 HB, in hot-rolled plate, sections and coil for welded load-bearing structures. It is chosen where Q355 sections would be too heavy, but weldability is more demanding (preheat and heat-input control on thick or high-CEV plate) and bare corrosion resistance is nil unless the NH weathering variant is used. Q460 has a density of 7.85 g/cm³ (0.284 lb/in³), heavier than 56% of steel grades. It melts at 1,420°C (2,588 °F). Q460 has a yield strength of 500 MPa (72.5 ksi) and a tensile strength of 620 MPa (89.9 ksi) — stronger than 63% of steel grades. Elongation at break is 21% and the elastic modulus is 206 GPa (29.9 Msi).
What is Q460 used for?
- Bridges
- Crane structures
- Industrial frames
Limitations
- Hard to polish — 45/100, worse than 84% of steel grades
Q460 properties
Typical room-temperature values for Q460-HR; bars are the position among steel grades.
Physical3
Q460 has a density of 7.85 g/cm³ (0.284 lb/in³), heavier than 56% of steel grades. It melts at 1,420°C (2,588 °F).
Mechanical16
Q460 has a yield strength of 500 MPa (72.5 ksi) and a tensile strength of 620 MPa (89.9 ksi) — stronger than 63% of steel grades. Elongation at break is 21% and the elastic modulus is 206 GPa (29.9 Msi).
Thermal6
Q460 is rated for continuous service to 350°C (662 °F). It conducts heat at 45 W/m·K (26 BTU/hr·ft·°F), better than 66% of steel grades. Thermal expansion is 12 µm/m·K (6.67 µin/in·°F).
Electrical3
Q460 conducts electricity at 8.2 % IACS, better than 61% of steel grades.
Chemical & Environmental3
Corrosion resistance is not recommended (12/100), worse than 53% of steel grades.
Sustainability4
Producing a kilogram of Q460 takes about 26 MJ of energy and emits 2.1 kg of CO₂ — less than 64% of steel grades. Typical recycled content is 25%.
Manufacturability8
Q460's machinability is fair (52/100, better than 52% of steel grades); weldability very good (70/100); formability good (55/100).
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. Q460 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with Q460
Is Q460 easy to machine?
Cuts like a tough 500 MPa-yield HSLA steel — use rigid setups, coated carbide at ~120–180 m/min and positive feeds to avoid work hardening; drilling and tapping are noticeably harder than Q235.
Can Q460 be welded?
Readily welded by SMAW/GMAW/SAW with 550–620 MPa class consumables; keep heat input moderate, preheat ~100–150 °C above 25–30 mm or with high CEV, and avoid over-welding TMCP plate to prevent HAZ softening.
Can Q460 be formed, bent or molded?
Cold bends to the GB/T 1591 mandrel with generous radii (≥2.5–3 t) and springback allowance; hot forming should stay below the normalizing/TMCP temperature or properties must be re-established by heat treatment.
Manufacturability
The process limits FabDigit applies to Q460. Every Q460 part is priced by an engineer; design inside these and the quote comes back without a redesign loop.
CNC machining
| Machinability | Better52 / 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 | Excellent55 / 100 |
|---|---|
| Weldability | Excellent70 / 100 |
| Bendable | Yes |
Q460 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≤0.20 for as-rolled Q460C; ≤0.16 for Q460M | ≤ 0.2 | 0.16 |
| Si | ≤ 0.6 | 0.3 |
| Mn | 1 – 1.8 | 1.55 |
| P≤0.025 for D, ≤0.020 for E/F class | ≤ 0.03 | 0.02 |
| S≤0.020 for D, ≤0.010 for E/F class | ≤ 0.03 | 0.01 |
| Nbmicro-alloying | ≤ 0.11 | 0.04 |
| Vmicro-alloying | ≤ 0.2 | 0.06 |
| Timicro-alloying | ≤ 0.2 | 0.02 |
| Cr | ≤ 0.3 | 0.1 |
| Ni | ≤ 0.8 | 0.15 |
| Cu | ≤ 0.4 | 0.15 |
| Mo | ≤ 0.2 | 0.05 |
| Altotal Al, fine-grain practice | ≥ 0.02 | 0.03 |
| N | ≤ 0.02 | 0.01 |
| Fe | balance |
What surface finishes work on Q460?
No anodizing; shot-blast to Sa 2.5 then zinc-rich epoxy, hot-dip galvanize (watch Si/P for coating appearance) or use the NH weathering variant for bare exposure.
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
Equivalent designations
Standards and trade names that resolve to Steel Q460 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
How much does Q460 cost?
Q460 is a budget-cost steel ($), cheaper than about 99% 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.
Q460 — frequently asked
What is Q460 used for?
Q460 is typically used for bridges, crane structures and industrial frames. In short: high-strength structural plate.
What is the yield strength of Q460?
Q460 has a typical yield strength of 500 MPa (72.5 ksi) and a tensile strength of 620 MPa (89.9 ksi) — stronger than 63% of steel grades. Strength varies by condition: see the 6 listed tempers.
Is Q460 easy to machine?
Reasonably — machinability is rated fair (52/100, better than 52% of steel grades). Cuts like a tough 500 MPa-yield HSLA steel — use rigid setups, coated carbide at ~120–180 m/min and positive feeds to avoid work hardening; drilling and tapping are noticeably harder than Q235.
Can Q460 be welded?
Yes — weldability is rated very good (70/100). Readily welded by SMAW/GMAW/SAW with 550–620 MPa class consumables; keep heat input moderate, preheat ~100–150 °C above 25–30 mm or with high CEV, and avoid over-welding TMCP plate to prevent HAZ softening.
What surface finishes work on Q460?
No anodizing; shot-blast to Sa 2.5 then zinc-rich epoxy, hot-dip galvanize (watch Si/P for coating appearance) or use the NH weathering variant for bare exposure.
Can Q460 be formed, bent or molded?
Cold bends to the GB/T 1591 mandrel with generous radii (≥2.5–3 t) and springback allowance; hot forming should stay below the normalizing/TMCP temperature or properties must be re-established by heat treatment.
What is the maximum service temperature of Q460?
Q460 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 Q460-HR and Q460-M?
HR is the default condition — standard stocked condition for plate, sections and coil where service temperature stays at or above 0 °C. M: pick for the leanest carbon equivalent and best field weldability with low-temperature toughness, typically in thick plate. Yield strength is 500 MPa in HR versus 510 MPa in M.
How much does Q460 cost?
Q460 is a budget-cost steel ($), cheaper than about 99% 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 Q460?
Yes — Q460 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
- GB/T 1591 High strength low alloy structural steels (2018)
- GB/T 19879 Steel plates for building structure — SAC (2015)
- GB/T 714 Structural steel for bridge — SAC (2015)
- GB/T 4171 Atmospheric corrosion resisting structural steel — SAC (2008)
- GB 50017 Standard for design of steel structures — MOHURD (2017)
- 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)
- Mysteel / SMM (Q460C) (2026)
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.