... high strengthen bolts,nuts, plates, washers ,flange, tension rod ,crane etc. Model: How to process the steel material We have our own factory ... manual , we can explain it on line, till finish it . If your workers don't know how to install , we can send our engineer ... Industrial Zone, Chengyang District, Qingdao City. We possess a factory with a construction area of 25,000 square meters and monthly ...