Steel S690Q
EN S690Q · GB Q690Q
S690Q is the EN 10025-6 quenched-and-tempered structural plate grade with 690 MPa minimum yield, also listed as Q690Q.
Reference datasheet — S690Q 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 Q condition
S690Q tempers and conditions
S690Q is supplied in 6 conditions, soft to hard. Q 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 |
|---|---|---|---|---|---|---|
Q&T, plate thickness 100–150 mm | Very heavy plate; lowest guaranteed properties of the grade and the practical thickness ceiling for S690. | 690 | 790 | 16 | 22 HRC | 7.5 % IACS |
Q&T, plate thickness 50–100 mm | Heavy plate condition — standard permits reduced guaranteed yield/tensile because of lower quench severity through thickness. | 710 | 830 | 16 | 24 HRC | 7.5 % IACS |
Stress relieved | Post-weld stress relief below the tempering temperature for dimensionally critical or thick welded assemblies; expect a small strength drop. | 720 | 810 | 17 | 24 HRC | 7.5 % IACS |
QDefault S690Q | Standard stocked quality for general high-strength welded structures operating down to about −20 °C. | 750 | 840 | 16 | 25 HRC | 7.5 % IACS |
S690QL | Choose when service or test temperature reaches −40 °C (cranes, arctic vehicles, offshore topsides); tighter P/S limits. | 755 | 845 | 16 | 25 HRC | 7.5 % IACS |
S690QL1 | Highest toughness class for cryogenic-service structures and heavy offshore sections down to −60 °C. | 760 | 850 | 17 | 24 HRC | 7.5 % IACS |
What is S690Q?
S690Q is the EN 10025-6 quenched-and-tempered structural plate grade with 690 MPa minimum yield, also listed as Q690Q. It is the standard choice for lightweight high-strength welded structures; typical plate shows 750 MPa yield, 840 MPa tensile, 16 % elongation and about 260 HB, with QL and QL1 sub-grades for low-temperature toughness, thickness-graded QT deliveries in 50–100 mm and 100–150 mm, and a stress-relieved condition. Cold bending needs 3–4 t radii and welding needs low-hydrogen consumables with preheat; A514 Grade B is the closest ASTM equivalent and S890Q the next strength step. S690Q 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). S690Q has a yield strength of 750 MPa (109 ksi) and a tensile strength of 840 MPa (122 ksi) — stronger than 84% of steel grades. Elongation at break is 16% and the elastic modulus is 210 GPa (30.5 Msi).
What is S690Q used for?
- cranes
- mobile equipment chassis
- structural fabrications
- trailers
Advantages
- Tough — resists crack growth — 130 MPa·√m (118.3 ksi·√in), better than 89% of steel grades
- High strength — 750 MPa (109 ksi), better than 84% of steel grades
Limitations
- Difficult to machine — 38/100, worse than 80% of steel grades
S690Q properties
Typical room-temperature values for S690Q-Q; bars are the position among steel grades.
Physical3
S690Q 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
S690Q has a yield strength of 750 MPa (109 ksi) and a tensile strength of 840 MPa (122 ksi) — stronger than 84% of steel grades. Elongation at break is 16% and the elastic modulus is 210 GPa (30.5 Msi).
Thermal6
S690Q is rated for continuous service to 400°C (752 °F). It conducts heat at 40 W/m·K (23.1 BTU/hr·ft·°F), worse than 64% of steel grades. Thermal expansion is 12 µm/m·K (6.67 µin/in·°F).
Electrical3
S690Q conducts electricity at 7.5 % IACS, worse than 67% of steel grades.
Chemical & Environmental3
Corrosion resistance is not recommended (14/100), better than 70% of steel grades.
Sustainability4
Producing a kilogram of S690Q takes about 29 MJ of energy and emits 2.3 kg of CO₂ — less than 53% of steel grades. Typical recycled content is 25%.
Manufacturability7
S690Q's machinability is fair (38/100, worse than 80% of steel grades); weldability good (65/100); 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. S690Q is highlighted; hover a dot for its name, or open the interactive family chart.
Working with S690Q
Is S690Q easy to machine?
Machine with rigid setups and coated carbide at moderate speed (roughly 60–110 m/min) and generous feed; the tough tempered structure work-hardens edges and dulls HSS quickly.
Can S690Q be welded?
Fully weldable with low-hydrogen (H5) 690-class consumables; keep hydrogen out, preheat typically 100–175 °C by thickness/CEV, control interpass ≤ 200 °C and limit heat input to protect HAZ toughness and avoid softening.
Can S690Q be formed, bent or molded?
Cold bend transverse to rolling direction with punch radii of about 3–4 × t (larger for thick plate); hot forming above the tempering temperature destroys the Q&T properties and requires re-heat-treatment.
S690Q 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 |
|---|---|---|
| Cladle analysis, t ≤ 50 mm | ≤ 0.2 | 0.16 |
| Si | ≤ 0.8 | 0.3 |
| Mn | ≤ 1.7 | 1.3 |
| P0.020 max for QL, 0.020 max for QL1 | ≤ 0.03 | 0.01 |
| S0.010 max for QL and QL1 | ≤ 0.02 | 0 |
| Cr | ≤ 1.5 | 0.5 |
| Nihigher Ni for QL/QL1 toughness | ≤ 2 | 0.6 |
| Mo | ≤ 0.7 | 0.4 |
| Cu | ≤ 0.5 | 0.15 |
| V | ≤ 0.12 | 0.04 |
| Nb | ≤ 0.06 | 0.02 |
| Ti | ≤ 0.05 | 0.02 |
| Zr | ≤ 0.15 | |
| Bboron-treated for hardenability | ≤ 0.01 | 0 |
| N | ≤ 0.02 | 0.01 |
| Fe | balance |
What surface finishes work on S690Q?
Grit-blast to Sa 2½ and paint or metallize for corrosion protection; grind weld toes to improve fatigue life and avoid acid pickling or uncontrolled electroplating because of hydrogen-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
Equivalent designations
Standards and trade names that resolve to Steel S690Q in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- EN / DIN / Werkstoff-Nr.
- 10025-6
- GB (China)
- Q690Q
How much does S690Q cost?
S690Q 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.
S690Q — frequently asked
What is S690Q used for?
S690Q is typically used for cranes, mobile equipment chassis, structural fabrications and trailers. In short: baseline EN 690 MPa plate; widely stocked Q&T plate; weight-saving structural steel.
What is the yield strength of S690Q?
S690Q has a typical yield strength of 750 MPa (109 ksi) and a tensile strength of 840 MPa (122 ksi) — stronger than 84% of steel grades. Strength varies by condition: see the 6 listed tempers.
Is S690Q easy to machine?
Not especially — machinability is rated fair (38/100, worse than 80% of steel grades). Machine with rigid setups and coated carbide at moderate speed (roughly 60–110 m/min) and generous feed; the tough tempered structure work-hardens edges and dulls HSS quickly.
Can S690Q be welded?
Yes — weldability is rated good (65/100). Fully weldable with low-hydrogen (H5) 690-class consumables; keep hydrogen out, preheat typically 100–175 °C by thickness/CEV, control interpass ≤ 200 °C and limit heat input to protect HAZ toughness and avoid softening.
What surface finishes work on S690Q?
Grit-blast to Sa 2½ and paint or metallize for corrosion protection; grind weld toes to improve fatigue life and avoid acid pickling or uncontrolled electroplating because of hydrogen-embrittlement risk.
Can S690Q be formed, bent or molded?
Cold bend transverse to rolling direction with punch radii of about 3–4 × t (larger for thick plate); hot forming above the tempering temperature destroys the Q&T properties and requires re-heat-treatment.
What is the maximum service temperature of S690Q?
S690Q 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 S690Q-Q and S690Q-SR?
Q is the default condition — standard stocked quality for general high-strength welded structures operating down to about −20 °C. SR: post-weld stress relief below the tempering temperature for dimensionally critical or thick welded assemblies; expect a small strength drop. Yield strength is 750 MPa in Q versus 720 MPa in SR.
How much does S690Q cost?
S690Q 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
- EN 10025-6: Hot rolled products of structural steels — Technical delivery conditions for flat products of high yield strength structural steels in the quenched and tempered condition — CEN (2019)
- GB/T 16270 High strength structural steel plates in the quenched and tempered condition (Q690D/E/F) — SAC (2009)
- High-strength quenched and tempered structural plate datasheets (S690Q/QL/QL1) — SSAB / Dillinger / voestalpine (2023)
- ASM Handbook Vol. 1 — Properties and Selection: Irons, Steels, and High-Performance Alloys — ASM International (1990)
- EN 1993-1-12 — Design of steel structures: additional rules for steel grades up to S700 — CEN (2007)
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.