... workshops and factory buildings, living quarters and ports. Bar Grating Trench Cover-Bar Grating:Trench cover has many advantages, such as easy construction, light ... treatment makes it good looking and long durability.This trench cover is widely used in city construction projects, gardens, workshops ... which 25,30,34,and 40mm are recommended.2.Cross bar pitches may be 24-200mm,of which 50mm,76mm ...