Spiral tensioner: lifting hook of a wire rope can lift 5 tons, two wire rope will be able to lift 10 tons, this concept is extremely inaccurate. Following the angle of the plumb line becomes larger, the force of the wire rope will be incessantly and significantly progress. Steel wire tensioner model wire rope, chain is quiet: some employees think that the wire rope sub-fit and chain of the quiet factor is very high, ordinary will not overload, even if overload wire rope breakage when another sign, but this unified condition is in the spreader without defect and without damage. In the reality of the use of often divergent degrees of wear and tear spreader, if the wear and tear severe spreader can be in the lifting rated load scale can suddenly break, tensioner manufacturers wire rope in the damaged environment will also be no signs of fracture, is to often search real-time scrapping. 3, single plate lifting pliers on the rated tonnage number is a load, two should be twice, the concept is not completely accurate. Because the veneer lifting pliers are used in pairs, so most of the factory industrial pliers on the rated tonnage is a pair of load amount, a few manufacturers exceptions, so use before the specific inspection statement.