辙叉磨床
railroad crossing grinder
高锰钢辙叉
high manganese steel frog
High manganese frog
high manganese steel crossing
高锰钢辙叉及护轨
high manganese steel rail and guard rail
可动心轨辙叉
Crossing with movable frogs
movable point frog
Movable-point Frog
锰钢辙叉
manganese steel frog crossing
manganese swi-tch
辙叉焊补
frog welding and repairing