| Grade | Compsition Chemical (Max %) | ||||
| C | Si | Mn | P | S | |
| STKR400 | 0.25 | - | - | 0.04 | 0.04 |
| STKR490 | 0.18 | 0.55 | 1.5 | 0.04 | 0.04 |
| Grade | Yeild Strength min Mpa | Tensile Strength min Mpa | Elongation(%) |
| STKR400 | 245 | 400 | 23 |
| STKR490 | 325 | 490 | 23 |
Ⅴ. Package: 
Ⅵ. Loading: 
Ⅶ. Further Processing: 
Ⅷ. Application: Alloy square tubes are used in construction, machinery manufacturing, steel construction projects, shipbuilding, solar power brackets, steel structure engineering, power engineering, power plants, agricultural and chemical machinery, glass curtain walls, automobile chassis, airports, etc. Ⅸ. Quality Control: 
Ⅹ. Our Service： 
Ⅺ. RFQ: Q1: Are you manufacture or Trader A: We are both manufacture and trader Q2: Can you offer sample? A: Sample small one can be offered by free, but buyer should pay the express fee Q3: Can you offer processing service? A: We can offer cutting, drilling, painting, coat powder etc... Q4: What is your advantage on steel? A: We can customize steel structure accoridng to buy's drawings or request. Q5: How about your logistic service? A: we have professional logistic team who has rich experience on shipping, can offer the steady and quality ship line.