... Qingdao Baoduo Steel Structure Co.,LTD.) is profession manufacturer of light and heavy steel structure buildings and welded steel parts in ... mistakes of others;Correct dishonest practices to form a righteous atmosphere;Go all out to create a famous brand, and honesty is essential ... bolts,nuts, plates, washers ,flange, tension rod ,crane etc. 4) How to order Design Parameters 1) Live load on roof (KN/M2 ...