| 摘要 |
Self drilling screws and other fastening devices tend to leave drill chips on outer surfaces of metal cladding sheets through which they pass and these chips can corrode and cause deterioration of such sheets. This problem is solved in accordance with the present invention by providing a washer (20) through which the fastening device (10) may pass and which includes a cavity (33) which captures and retains drill chips as they are formed. The washer (20) may be positively locatable on the drill point (15) of the fastening member (10) and the cavity (33) can be formed by a skirt region adapted to surround the fastening device (10). In one aspect, the cavity (33) may include a mastic or like material (22) capable of securely holding drill chips. |
