... construction, which mainly applies to such base constructions as railway,road,bridge, public works bridge and large building,etc. ... .P.A.(including caterpillar assembly,driving roller, guiding roller,track roller,carrier roller,etc.). 4,Power head—main body ... /min2.5We are Shandong Hongda Construction Machinery Group Co., Ltd., a professional construction machinery manufacturer with a history of 28 ...