Some factors which could affect the Bumpy-ridge coefficient were experimented. On a series of experiments, it is found that Bumpy-ridge coefficient is obviously larger than friction coefficient. To a degree, various figures of interactions between Bumpy-ridge structures will affect Bumpy-ridge coefficient. As the pre-force is improved, Bumpy-ridge coefficient will increase to a steady value therefore. The alternative load will not destroy Bumpy-ridge connection. Instead, it is helpful to the self-adaptive effect of Bumpy-ridge structure. In practice, Bumpy-ridge structure has been successfully applied to several engineering projects.