五类型材默认参数对比(a=20mm / b=10mm / t=3mm / L=6m)
按碳钢密度 7.85 g/cm³ 推导的经验系数(圆钢 0.00617、方钢/扁钢/角钢 0.00785):
圆钢 a²×0.00617 = 20²×0.00617 = 2.468 kg/m,总重 2.468×6 ≈ 14.81 kg;
方钢 a²×0.00785 = 3.14 kg/m,总重 18.84 kg;
扁钢 a×b×0.00785 = 20×10×0.00785 = 1.57 kg/m,总重 9.42 kg;
等边角钢 (2a−t)×t×0.00785 = (40−3)×3×0.00785 = 0.871 kg/m,总重 5.23 kg;
槽钢 (a+b−2t)×t×0.00785×1.05 = (20+10−6)×3×0.00785×1.05 = 0.593 kg/m,总重 3.56 kg(×1.05 含腿端加厚修正)。