| 1. | Timber structures - strength classes ; german version en 338 : 2003 木材结构.强度等级 |
| 2. | Strength classes grades of prestressed tendon 预应力筋强度等级30 |
| 3. | Strength classes grades of steel barokok . org 普通钢筋强度等级30 |
| 4. | Minimum strength class of masonry 砌体材料最低强度等级47 |
| 5. | Structural timber - strength classes 结构木材.强度等级 |
| 6. | Structural timber - strength classes 结构木材.强度类型 |
| 7. | Strength classes of structural timber 木材强度等级66 |
| 8. | Strength classes grades of steel bar 普通钢筋强度等级 |
| 9. | Strength classes grades of concrete 混凝土强度等级29 |
| 10. | Strength classes of structural steel 钢材强度等级55 |