S690QL is characterized by its high yield strength, typically around 690 MPa (100 ksi), which allows for thinner sections in structural applications without compromising load-bearing capacity. This property makes it particularly advantageous in industries such as construction, mining, and heavy machinery, where weight reduction is crucial. The steel exhibits excellent toughness and ductility, ensuring that it can withstand dynamic loads and impact forces.

Advantages:
- High Strength-to-Weight Ratio: Enables the design of lighter structures.
- Good Weldability: Suitable for various welding processes, facilitating fabrication.
- Excellent Toughness: Maintains performance in low-temperature environments.
Limitations:
- Cost: Higher than conventional mild steels due to alloying elements and processing.
- Corrosion Resistance: While it has decent resistance, it may require protective coatings in aggressive environments.
S690QL has gained popularity in the market due to its ability to meet stringent performance criteria while providing cost-effective solutions in structural applications. Its historical significance lies in its development to meet the increasing demands for high-performance materials in modern engineering.
Alternative Names, Standards, and Equivalents
| Standard Organization | Designation/Grade | Country/Region of Origin | Notes/Remarks |
|---|---|---|---|
| UNS | S690QL | USA | Closest equivalent to EN 10025-6 |
| EN | S690QL | Europe | High yield strength structural steel |
| ASTM | A709 Grade 50QL | USA | Similar properties, used in bridge applications |
| DIN | 1.8928 | Germany | Equivalent grade with minor compositional differences |
| JIS | - | Japan | No direct equivalent, but similar grades exist |
The table above highlights various standards and equivalent grades for S690QL. Notably, while ASTM A709 Grade 50QL shares similar mechanical properties, it may differ in chemical composition, which could affect performance in specific applications. Understanding these nuances is crucial for material selection.
Key Properties
-
Chemical Composition of S690QL Plasma Cutting Steel Plates
| Grade | C | Si | Mn | P | S | N | B | Cr | Cu | Mo | Nb* | Ni | Ti* | V* | Zr* |
| S690QL | 0.20 | 0.80 | 1.70 | 0.025 | 0.015 | 0.015 | 0.0050 | 1.50 | 0.50 | 0.70 | 0.06 | 2.0 | 0.05 | 0.12 | 0.15 |
-
Mechanical Properties of S690QL Plasma Cutting Steel Plates
| Designation | Mechanical Properties (ambient temperature) | |||||||
| Steel Name | Steel Number | Min. Yield Strength Reh MPa | Tensile Strength Rm MPa | Min. % elongation after fracture | ||||
| Nominal thickness (mm) | Nominal thickness (mm) | |||||||
| ≥3 ≤50 | ≥50 ≤100 | ≥100 ≤150 | ≥3 ≤5 | ≥50 ≤100 | ≥100 ≤150 | |||
| S690QL | 1.8931 | 690 | 650 | 630 | 770/940 | 760/930 | 710/900 | 14 |
-
Physical Properties
| Property | Condition/Temperature | Value (Metric) | Value (Imperial) |
|---|---|---|---|
| Density | - | 7.85 g/cm³ | 0.284 lb/in³ |
| Melting Point | - | 1420 - 1460 °C | 2590 - 2660 °F |
| Thermal Conductivity | 20°C | 50 W/m·K | 34.5 BTU·in/h·ft²·°F |
| Specific Heat Capacity | 20°C | 0.49 kJ/kg·K | 0.12 BTU/lb·°F |
| Coefficient of Thermal Expansion | 20 - 100 °C | 12 x 10⁻⁶/K | 6.67 x 10⁻⁶/°F |
Key physical properties such as density and thermal conductivity are significant for applications where weight and heat dissipation are critical. The relatively high melting point indicates good performance under elevated temperatures.
Typical Applications and End Uses
| Industry/Sector | Specific Application Example | Key Steel Properties Utilized in this Application | Reason for Selection |
|---|---|---|---|
| Construction | High-rise buildings | High yield strength, good weldability | Reduces structural weight |
| Mining | Excavators | Toughness, impact resistance | Endures harsh conditions |
| Heavy Machinery | Cranes | High tensile strength | Supports heavy loads |
| Offshore Structures | Oil rigs | Corrosion resistance, strength | Operates in marine environments |
Other applications include:
- Bridges: Utilizing high strength for reduced material use.
- Transport Equipment: Lightweight structures for efficiency.
S690QL is chosen for these applications due to its ability to meet stringent performance requirements while providing cost-effective solutions.
Important Considerations, Selection Criteria, and Further Insights
| Feature/Property | S690QL | S355 | S700MC | Brief Pro/Con or Trade-off Note |
|---|---|---|---|---|
| Key Mechanical Property | High Yield Strength | Moderate Yield Strength | Higher Yield Strength | S690QL offers a balance of strength and weldability |
| Key Corrosion Aspect | Fair Resistance | Good Resistance | Fair Resistance | S355 may be better for corrosive environments |
| Weldability | Good | Excellent | Fair | S690QL requires careful handling |
| Machinability | Moderate | Good | Moderate | S355 is easier to machine |
| Formability | Limited | Good | Moderate | S690QL is less formable |
| Approx. Relative Cost | Higher | Lower | Higher | Cost considerations vary by application |
| Typical Availability | Moderate | High | Moderate | S355 is widely available |
When selecting S690QL, considerations include cost-effectiveness, availability, and specific application requirements. While it offers superior strength, its higher cost and moderate machinability may influence decisions in favor of alternative grades in less demanding applications. Additionally, safety factors and potential for fatigue failure should be evaluated in design processes.
If you want to learn more about GNEE's products, you can send an email to info@gneesteels.com. We are more than happy to assist you.



FAQ
Q: What is the difference between S690QL and S690Q?
A: S690Q: Minimum impact toughness tested at -20°C (30J average). → Typical Use: Cranes in temperate climates, quarry equipment. S690QL: Certified for -40°C and below (≥40J impact toughness). → Critical Use: Arctic pipelines, offshore platforms, mining vehicles in Siberia.
Q: What is S690 grade steel?
A: S690 high yield & fine grain steel plate is a high strength, quenched and tempered fine-grain structural steel. Structural steel S690 is used in structures that must withstand very heavy loads. This grade is meant for structures where weight savings is important.
Q: What is S690QL material?
A: S690QL is a high strength quenched and tempered steel grade that complies to steel specification EN 10025. The designation S690QL refers to a minimum yield strength of 690 MPa.
Q: What is S690 steel?
A: S690 high yield & fine grain steel plate is a high strength, quenched and tempered fine-grain structural steel. Structural steel S690 is used in structures that must withstand very heavy loads. This grade is meant for structures where weight savings is important.
Q: What is the equivalent of S690 steel?
A: Equivalent grades to S690QL steel include ASTM A709-100 (USA), E690T and S690T (France), TStE690V and DILLIMAX 690 (Germany), WELDOX 700 (Sweden), and E690 (ISO). These equivalents are specific to different regional standards and manufacturers, but they all share similar high-strength, quenched and tempered properties.
Q: What material group is S690?
A: S690 QL is a high yield structural steel grade produced in compliance with EN 10025:6:2004. The material is heat treated using the quench and temper process and has good bending and welding properties.
| Grades Of Carbon and Low-alloy High-strength Steels Supplied By GNEE | |||||
| ASTM/ASME | ASTM A36/A36M | ASTM A36 | |||
| ASTM A283/A283M | ASTM A283 Grade A | ASTM A283 Grade B | ASTM A283 Grade C | ASTM A283 Grade D | |
| ASTM A514/A514M | ASTM A514 Grade A | ASTM A514 Grade B | ASTM A514 Grade C | ASTM A514 Grade E | |
| ASTM A514 Grade F | ASTM A514 Grade H | ASTM A514 Grade J | ASTM A514 Grade K | ||
| ASTM A514 Grade M | ASTM A514 Grade P | ASTM A514 Grade Q | ASTM A514 Grade R | ||
| ASTM A514 Grade S | ASTM A514 Grade T | ||||
| ASTM A572/A572M | ASTM A572 Grade 42 | ASTM A572 Grade 50 | ASTM A572 Grade 55 | ASTM A572 Grade 60 | |
| ASTM A572 Grade 65 | |||||
| ASTM A573/A573M | ASTM A573 Grade 58 | ASTM A573 Grade 65 | ASTM A573 Grade 70 | ||
| ASTM A588/A588M | ASTM A588 Grade A | ASTM A588 Grade B | ASTM A588 Grade C | ASTM A588 Grade K | |
| ASTM A633/A633M | ASTM A633 Grade A | ASTM A633 Grade C | ASTM A633 Grade D | ASTM A633 Grade E | |
| ASTM A656/A656M | ASTM A656 Grade 50 | ASTM A656 Grade 60 | ASTM A656 Grade 70 | ASTM A656 Grade 80 | |
| ASTM A709/A709M | ASTM A709 Grade 36 | ASTM A709 Grade 50 | ASTM A709 Grade 50S | ASTM A709 Grade 50W | |
| ASTM A709 Grade HPS 50W | ASTM A709 Grade HPS 70W | ASTM A709 Grade 100 | ASTM A709 Grade 100W | ||
| ASTM A709 Grade HPS 100W | |||||
| ASME SA36/SA36M | ASME SA36 | ||||
| ASME SA283/SA283M | ASME SA283 Grade A | ASME SA283 Grade B | ASME SA283 Grade C | ASME SA283 Grade D | |
| ASME SA514/SA514M | ASME SA514 Grade A | ASME SA514 Grade B | ASME SA514 Grade C | ASME SA514 Grade E | |
| ASME SA514 Grade F | ASME SA514 Grade H | ASME SA514 Grade J | ASME SA514 Grade K | ||
| ASME SA514 Grade M | ASME SA514 Grade P | ASME SA514 Grade Q | ASME SA514 Grade R | ||
| ASME SA514 Grade S | ASME SA514 Grade T | ||||
| ASME SA572/SA572M | ASME SA572 Grade 42 | ASME SA572 Grade 50 | ASME SA572 Grade 55 | ASME SA572 Grade 60 | |
| ASME SA572 Grade 65 | |||||
| ASME SA573/SA573M | ASME SA573 Grade 58 | ASME SA573 Grade 65 | ASME SA573 Grade 70 | ||
| ASME SA588/SA588M | ASME SA588 Grade A | ASME SA588 Grade B | ASME SA588 Grade C | ASME SA588 Grade K | |
| ASME SA633/SA633M | ASME SA633 Grade A | ASME SA633 Grade C | ASME SA633 Grade D | ASME SA633 Grade E | |
| ASME SA656/SA656M | ASME SA656 Grade 50 | ASME SA656 Grade 60 | ASME SA656 Grade 70 | ASME SA656 Grade 80 | |
| ASME SA709/SA709M | ASME SA709 Grade 36 | ASME SA709 Grade 50 | ASME SA709 Grade 50S | ASME SA709 Grade 50W | |
| ASME SA709 Grade HPS 50W | ASME SA709 Grade HPS 70W | ASME SA709 Grade 100 | ASME SA709 Grade 100W | ||
| ASME SA709 Grade HPS 100W | |||||
| EN10025 | EN10025-2 | EN10025-2 S235J0 | EN10025-2 S275J0 | EN10025-2 S355J0 | EN10025-2 S355K2 |
| EN10025-2 S235JR | EN10025-2 S275JR | EN10025-2 S355JR | EN10025-2 S420J0 | ||
| EN10025-2 S235J2 | EN10025-2 S275J2 | EN10025-2 S355J2 | |||
| EN10025-3 | EN10025-3 S275N | EN10025-3 S355N | EN10025-3 S420N | EN10025-3 S460N | |
| EN10025-3 S275NL | EN10025-3 S355NL | EN10025-3 S420NL | EN10025-3 S460NL | ||
| EN10025-4 | EN10025-4 S275M | EN10025-4 S355M | EN10025-4 S420M | EN10025-4 S460M | |
| EN10025-4 S275ML | EN10025-4 S355ML | EN10025-4 S420ML | EN10025-4 S460ML | ||
| EN10025-6 | EN10025-6 S460Q | EN10025-6 S460QL | EN10025-6 S460QL1 | EN10025-6 S500Q | |
| EN10025-6 S500QL | EN10025-6 S500QL1 | EN10025-6 S550Q | EN10025-6 S550QL | ||
| EN10025-6 S550QL1 | EN10025-6 S620Q | EN10025-6 S620QL | EN10025-6 S620QL1 | ||
| EN10025-6 S690Q | EN10025-6 S690QL | EN10025-6 S690Q1 | EN10025-6 S890Q | ||
| EN10025-6 S890QL | EN10025-6 S890QL1 | EN10025-6 S960Q | EN10025-6 S960QL | ||
| EN 10149 | EN 10149-2 | S315MC | S355MC | S420MC | S460MC |
| S500MC | S550MC | S600MC | S650MC | ||
| S700MC | S900MC | S960MC | |||
| JIS | JIS G3101 | JIS G3101 SS330 | JIS G3101 SS400 | JIS G3101 SS490 | JIS G3101 SS540 |
| JIS G3106 | JIS G3106 SM400A | JIS G3106 SM400B | JIS G3106 SM400C | JIS G3106 SM490A | |
| JIS G3106 SM490YA | JIS G3106 SM490B | JIS G3106 SM490YB | JIS G3106 SM490C | ||
| JIS G3106 SM520B | JIS G3106 SM520C | JIS G3106 SM570 | |||
| DIN | DIN 17100 | DIN17100 St52-3 | DIN17100 St37-2 | DIN17100 St37-3 | DIN17100 RSt37-2 |
| DIN17100 USt37-2 | |||||
| DIN 17102 | DIN17102 StE315 | DIN17102 EStE315 | DIN17102 TStE315 | DIN17102 WStE315 | |
| DIN17102 StE355 | DIN17102 EStE355 | DIN17102 TStE355 | DIN17102 WStE355 | ||
| DIN17102 StE380 | DIN17102 EStE380 | DIN17102 TStE380 | DIN17102 WStE380 | ||
| DIN17102 StE420 | DIN17102 EStE420 | DIN17102 TStE420 | DIN17102 WStE420 | ||
| DIN17102 StE460 | DIN17102 EStE460 | DIN17102 TStE460 | DIN17102 WStE460 | ||
| DIN17102 StE500 | DIN17102 EStE500 | DIN17102 TStE500 | DIN17102 WStE500 | ||
| DIN17102 EStE285 | |||||
| GB | GB/T700 | GB/T700 Q235A | GB/T700 Q235B | GB/T700 Q235C | GB/T700 Q235D |
| GB/T700 Q275 | |||||
| GB/T1591 | GB/T1591 Q345A | GB/T1591 Q390A | GB/T1591 Q420A | GB/T1591 Q420E | |
| GB/T1591 Q345B | GB/T1591 Q390B | GB/T1591 Q420B | GB/T1591 Q460C | ||
| GB/T1591 Q345C | GB/T1591 Q390C | GB/T1591 Q420C | GB/T1591 Q460D | ||
| GB/T1591 Q345D | GB/T1591 Q390D | GB/T1591 Q420D | GB/T1591 Q460E | ||
| GB/T1591 Q345E | GB/T1591 Q390E | ||||
| GB/T16270 | GB/T16270 Q550C | GB/T16270 Q550D | GB/T16270 Q550E | GB/T16270 Q550F | |
| GB/T16270 Q620C | GB/T16270 Q620D | GB/T16270 Q620E | GB/T16270 Q620F | ||
| GB/T16270 Q690C | GB/T16270 Q690D | GB/T16270 Q690E | GB/T16270 Q690F | ||
| GB/T16270 Q800C | GB/T16270 Q800D | GB/T16270 Q800E | GB/T16270 Q800F | ||
| GB/T16270 Q890C | GB/T16270 Q890D | GB/T16270 Q890E | GB/T16270 Q890F | ||
| GB/T16270 Q960C | GB/T16270 Q960D | GB/T16270 Q960E | GB/T16270 Q960F | ||
| GB/T16270 Q500 | |||||




