[구조용 강관] 호 칭 바깥지름 허용오차 두 께 Skelp폭 중 량 本/M S inch mm mm mm mm (kg/m) T 15 5/8 15.9 ±0.20 1.5 48.0 0.435 383 47.6 0.533 312 19 3/4 19.1 ±0.20 1.5 58.1 0.530 314 57.6 0.651 256 22 7/8 22.2 ±0.20 1.5 67.8 0.621 268 67.3 0.766 217 25 1 25.4 ±0.20 1.5 77.9 0.761 232 77.4 0.884 188 28 1⅛ 28.6 ±0.20 1.5 87.4 0.811 205 87.9 1.002 166 31 1¼ 31.8 ±0.20 1.5 98.0 1.906 183 97.5 1.121 148 38 1½ 38.1 ±0.20 1.5 117.8 1.092 152 117.3 1.354 123 50 2 50.8 ±0.25 1.5 157.6 1.468 113 157.1 1.824 91 65 2½ 63.5 ±0.30 1.5 197.0 2.294 72 75 3 76.2 ±0.35 1.5 236.0 2.763 60 100 4 101.6 ±0.50 1.5 316.0 3.702 22