The destructive mechanism of self-drilling screws connection is recorded in the test.
试验结果表明：自攻自钻螺钉群连接件具有“群体折减效应”。
2
As the early morning of 23, the team found workers were self-drilling, grouting, installation, transportation equipment, and other operational risks 11 are to be corrected.
截止23日早班，该队职工共自查出打钻、注浆、安装、转运设备等操作上的隐患11条，均得以改正。
3
Furthermore, since the stud and wallboard are connected by self-drilling screws, the fastening pieces between steel and wallboard tests are taken to get the shear rigidity.