| 摘要 |
Provided is an elongate construction element including a rigid elongate tubular body formed with at least one longitudinal U-like shaped groove. The groove is defined between a pair of facing side walls and a base wall spanning therebetween. The side walls are each formed with a plurality of parallely extending, spaced apart longitudinal ribs projecting therefrom, which together mimic a portion of a nominal threaded bore. The groove is formed such that the ratio between the height of the groove and the distance between the side walls is no greater than 1.8. The axial force in newtons necessary to remove a screw threaded therein the groove and fully penetrating the base wall is less than 3.7 times the product of the tensile yield strength of the material of the construction element and the distance between the sidewalls in millimeters. |
