我是从事索结构产品的，由于需要，会涉及到耳板（连接板）的设计，耳板一般采用A3或16Mn，对于耳板的安全系数到底如何确定？我一般按拉索的破断等强度进行考虑，是否偏大？请各位指教。

Usually, the each component along the cable end connections has different design method. For example, the cables and its end pieces (jaw end, rigging screw, toggles etc. are proprietary products, of which the quality is controlled by various standards that basically falls into two catagories: proof load and minimum breaking loads(MBL). The design of such component is governed by a factor of safety (F.O.S), i.e. the design load of the component (cable and end piece) should be less than the minimum breaking load divided by FOS:
  
design load < MBL / FOS
  
The FOS for cables and end pieces is around 2 to 3
  
As for the steel plates etc that made from raw materials governed by national standard, the design methodology nowadays falls into limit states design. We have to be clear about the factor of safety enherent to the design methodology. The FOS for steel plates etc is around 1.3 to 1.5.
  
So you see the steel plate is the weakest component along the load path. But the quality of the cables and end pieces will vary sometimes. Randon sampling and test is necessary. This happens to some important projects that a certain percentage of the cables and end pieces will be selected on site and to be tested. I don't know if this is also the case in China.   
  
抱歉, 输入中文的速度太慢, 只好先用英文写. 以后会多努力.