Q690D vs S690QL
These two grades are listed as equivalents of each other: their chemistry windows overlap and they serve the same applications. They are not always identical — check the differences below before substituting, especially in certified designs.
Q690D
Structural & HSLA Steel
Q690D is China’s 690 MPa Q&T structural plate, produced by mills such as Wugang and Baowu for cranes, mining trucks and hydraulic supports. Quality D adds a −20 °C impact guarantee over the base grade.
Standards: DIN S690QL (near) · AISI A514 (near) · GB Q690D (GB/T 1591)
S690QL
Structural & HSLA Steel
S690QL is the EN 10025-6 quenched-and-tempered structural steel with 690 MPa minimum yield — the grade behind weight-critical crane booms, mining equipment and mobile machinery in Europe. Its low-temperature toughness (−40 °C) matches the strength, unlike cheaper Q&T plates.
Standards: DIN 1.8928 (S690QL) · AISI A514 (near) · GB Q690D (near)
Chemical composition compared (%)
| Element | Q690D | S690QL |
|---|---|---|
| C | ≤0.18 | ≤0.20 |
| Si | ≤0.50 | ≤0.80 |
| Mn | ≤2.00 | ≤1.70 |
| P | ≤0.025 | ≤0.020 |
| S | ≤0.020 | ≤0.010 |
| Cr | — | ≤1.50 |
| Ni | — | ≤2.00 |
| Mo | — | ≤0.70 |
| B | — | ≤0.005 |
Properties compared
| Property | Q690D | S690QL |
|---|---|---|
| Yield strength | ≥690 MPa (≤50 mm) | ≥690 MPa (≤50 mm) |
| Tensile strength | 770–940 MPa | 770–940 MPa |
| Impact | D grade: 34 J at −20 °C (typ.) | QL: 27 J at −40 °C |
| Density | 7.85 g/cm³ | 7.85 g/cm³ |
Sourcing either grade?
Nasteel stocks both families from Shenzhen with EN 10204 3.1 mill certificates by heat number.
Ask for a quotationSee full data sheets: Q690D · S690QL. Substitution decisions for certified parts stay with the design authority.