| 摘要 |
The element comprises a first threaded front part (1) for drilling and self-cutting, followed, to the rear, by a second threaded part (2) with a thread (13) which is larger than that (9) of the front part (1). The threads (9, 13) of the first front part (1) and the second part (2) extend over a common helix and are spaced apart (10, 14) from one another. The invention permits the assembly of two gypsum boards under good conditions. <IMAGE> |
