铜瓦与钢套的理想配合,应该是无论什么时候,其配合表面之间都必须有足够的预紧力,即有一定的过盈量,这是保证铜瓦使用寿命较长的重要条件之一。如果铜瓦与钢套之间存在间隙,则会使铜瓦内孔表面过早地产生“龟裂”、“起皮”,甚至使铜瓦断裂、报废。过去,我国和原苏联等国家,对铜瓦和钢套的配合均选用(H7)/(r6)(D/(Jf))、(H7)/(n6)(D/(ga))、(H7)/(k6)(D/(gc))三种配合座。实践证明,这三种配合座并不适应各种室温变化的场合。例如我十堰地区,冬夏两季的 Copper wedge and the ideal fit, should be no matter when, with the surface must have sufficient pre-tightening force, that there is a certain amount of interference, which is to ensure that the long service life of the important conditions of the copper tile one. If there is a gap between the copper tile and the steel sleeve, the inner surface of the copper tile will prematurely produce “cracks”, “peeling” and even the copper tiles will be broken and discarded. In the past, China and the countries such as the former Soviet Union used (H7) / (r6) (D / (Jf)), (H7) / (n6) H7) / (k6) (D / (gc)) three kinds of seats. Practice has proved that these three seat does not adapt to a variety of room temperature changes in the occasion. For example, I Shiyan area, winter and summer two seasons