W = 0.00785 [250 10+2 13 (118 10)+0.615 (102 52)]=42.03(kg/m)
这些全部是工字钢的标准:
2. BS 227-1995 现行
Specification for H-section steel arches for use in mines
矿用工字钢钢拱规范
3. BS 4521-1.1-1971 现行
Specification for railway turnouts for private users - Turnouts over which British Railways locomotives operate - Turnouts using bull head rails
铁路道岔规范.第1部分:英国铁路机车运行道岔.第1节:工字钢轨道岔