H-Beam Steel Load Bearing Parameter Technical Manual
1.Analysis of the New National Standard Specification System
The new version of the GB/T 11263 standard in October 2024 simplifies H-shaped steel into two categories: General type (H) and Extended type (HK), with the following breakthroughs:
①.Addition of 24 ultra-large sizes (height > 1000mm)
②.Extension of maximum specifications to H1700×550mm
③.Standardization of cross-sectional property calculations
2.Load-Bearing Parameter Table
| Model Specification | Wx (cm³) | Bending Load Capacity (kN·m) | Weight (kg/m) | Applicable Span (m) |
| H400×200×8×13 | 2300 | 793.5 (Q345B) / 845.2 (Q355B) | 66.0 | ≤10 |
| H588×300×12×20 | 6220 | 2146.8 / 2286.4 | 151.0 | ≤18 |
| H900×300×16×28 | 13400 | 4623.0 / 4921.5 | 280.0 | ≤25 |
| HK1000×350×20×30 | 21500 | 7417.5 / 7896.0 | 398.0 | ≤30 |
Note: The load-bearing capacity of Q355B is 6.8% higher than Q345B (safety factor 1.5).
3.Key Points for Selection Technology
①. Bending Bearing Capacity = Section Modulus × Material StrengthWx = α × [b·h³ - (b·tw)·(h2tf)³] / (6h) (α for rolled steel 0.95-1.0, welded steel 0.85-0.95)
②.Tolerance Requirements: Web waviness < 3mm/m; flange bending deviation < L/750; weight ±5%
③.For welded structures, Q345B is preferred (impact in heat-affected zone ≥ 34J); thickness tolerance for dynamic load ±0.3mm
4.Typical Application Parameters
①.Main Beam of Industrial Plant: H600×300×14×23, load 85 kN/m, deflection limit L/4002.
②.Bridge Support: HK1200×400×24×35, compression 9800 kN, slenderness ratio λ ≤ 803.
③.Equipment Base: H400×400×13×21, torsional modulus 985 cm³, compression area 4800 mm²
5.Special Operating Condition Adjustments
①.High temperature > 200°C: strength reduction factor 0.9 (creep for welded seams 0.85)
②.Corrosive environment: wall thickness +2mm (+3mm for welded parts)
③.Alternating load: fatigue strength reduction factor 0.7 (rolled) / 0.6 (welded)
④. Seismic design: ductility factor 3.2 (welded parts require reinforcing ribs)
Prepared in accordance with GB/T11263-2024, engineering verification is required. Preferably use Q355B rolled steel; for welded steel, strengthen weld inspection and corrosion protection.
