| 摘要 |
A fastener (20) comprising a barrel portion (22), a flange portion (24) which extends radially from the barrel portion generally perpendicular thereto and a fastener portion (26) generally opposite the barrel portion (22), wherein said flange portion includes an outer annular panel bearing surface (23), is characterised in that an annular groove (40) is provided adjacent to and surrounding the barrel portion (22) radially inside the outer annular panel bearing surface (23) and in that a plurality of spaced radial ribs (42) bridge said groove (40) (Fig. 1). <IMAGE> |
