STKR400 is the Japanese Industrial Standard (JIS) designation for carbon steel square tubing used in mechanical structures. The primary standard for its welded square tubing is JIS G 3444 (Carbon Steel Tubes for Mechanical Structures). This standard specifies the following:
1. Material Requirements: The chemical composition of STKR400 must meet the following requirements: Carbon (C) ≤ 0.30%, Manganese (Mn) 0.60%-1.20%, ensuring stable weldability.
2. Dimensional Tolerances: The standard specifies an allowable deviation of ±1.0 mm for side length and ±10% for wall thickness (refer to Table 2 of JIS G 3444). For example, the actual side length range for a 50mm × 50mm square tubing is 49mm~51mm.
3. Mechanical Properties: Tensile strength ≥ 400MPa, yield strength ≥ 235MPa (Data source: JIS Standard 2021).
What is the chemical composition of STKR400 steel
| STKR400, JIS G 3466 | ||
| Chemical composition (%) | Carbon (C) | 0.25 max |
| Silicon (Si) | – | |
| Manganese (Mn) | – | |
| Phosphorus (P) | 0.040 max | |
| Sulfur (S) | 0.040 max | |
| Tensile strength (MPa) | 400 min | |
| Yield strength (MPa) | 245 min | |
| Elongation (%) | 23 min | |
What is the ASTM equivalent of STK400?
STKR400 is a structural steel in the Japanese Industrial Standard (JIS), primarily used for manufacturing square and rectangular tubing. In American standards, the corresponding or similar material standard is typically ASTM A500 Grade B.
JIS g3466 STK400 specifications
Grade: STKR 400, STKR 490
Square Size: 40*40mm-350*350mm
Rectangular Size: 20*50mm-200*400mm
Wall Thickness: 1.6-12mm
Corresponding standards: ASTM A500 Gr.A/B/C/D, EN 10219-1, EN 10210-1 S275JRH, S355J0H
JIS g3466 STK400 dimensions
| Table Dimensional Tolerances | |||
|---|---|---|---|
| Speclfied item and dimension | Dimensional tolerances | ||
| Length of side | 100 mm or under | ±1.5mm | |
| Over 100 mm | ±1.5% | ||
| Unevenness of flat plate portion of each side | Side length 100 mm or under | 0.5 mm max | |
| Side length over 100 mm | Within 0.5% of side length | ||
| Anguiarity made by adfacent flat plate portions | ±1.5% | ||
| Dimension at corner: s | 3mm max | ||
| Length | + not specifird 0 | ||
| Unstraightness | Within 0.3% of side length | ||
| Wall thickness | Square steel tube manufactured by welding | Under 3 mm | ±0.3mm |
| 3 mm or over | ±10% | ||
| Seamless square steel tube | Under 4 mm | ±0.6mm | |
| 4 mm or over | ±15% | ||
JIS G3466 STK400 structural tube for sale
