Q275 Mild Steel
Q275 steel is a Chinese carbon structural steel, “Q” is the first letter of Chinese spelling of “qu fu dian”, the translation is “Yield Point” or “Yield Strength”, “275” is short for the unit value “275 MPa”, and the tensile strength is 410-540 MPa (N/mm2), all data are tested with 16mm diameter steel bars or 16mm thickness steel plates.
The latest executive standard of Q275 steel is GB/T 700-2006, and chemical composition and physical properties are equivalent to JIS standard SS490, ISO standard E275A, no equivalent to ASTM standard.
Q275 steel has high strength, good plasticity and cutting performance, certain welding performance, small parts can be quenched and strengthened, and used for manufacturing parts with high strength, such as gears and shafts, sprocket, key, bolt, nut, steel for agricultural machinery, conveyor chain and chain link.
The following datasheets show the Q275 steel specifications and equivalents:
Table-1, Q275 Steel Chemical Composition
| Chemical Composition % | |||||||
| Steel Grade | Quality Grade | C (≤) | Si (≤) | Mn (≤) | P (≤) | S (≤) | Deoxidation |
| Q275 | Q275A | 0.24 | 0.35 | 1.50 | 0.045 | 0.050 | Rimmed / killed |
| Q275B | 0.21 | 0.35 | 1.50 | 0.045 | 0.045 | Killed | |
| Q275C | 0.22 | 0.35 | 1.50 | 0.040 | 0.040 | Killed | |
| Q275D | 0.20 | 0.35 | 1.50 | 0.035 | 0.035 | Exceptionally Killed | |
Quality Grade: A < B < C <D
Table-2, Q275 Steel Mechanical Property
| Steel Grade | Quality | Yield Strength (≥N/mm2) | Tensile Strength (N/mm2) | Elongation (≥%) | Impact Test (V notch) | ||||||||||
| Thickness or Dia. (d) mm | Thickness or Dia. (d) mm | Temp. ℃ | Absorbed Energy (Vertical, ≥J) | ||||||||||||
| d≤16 | 16< d ≤40 | 40< d ≤60 | 60< d ≤100 | 100< d ≤150 | 150< d ≤200 | d≤40 | 40< d ≤60 | 60< d ≤100 | 100< d ≤150 | 150< d ≤200 | |||||
| Q275 | Q275A | 275 | 265 | 255 | 245 | 225 | 215 | 410-540 | 22 | 21 | 20 | 18 | 17 | – | – |
| Q275B | +20 | 27 | |||||||||||||
| Q275C | 0 | ||||||||||||||
| Q275D | -20 | ||||||||||||||
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