The present invention relates to an apparatus for alterable accurate setting an angle between a first elongated member (1) and a second elongated member (2) without any angular play between said elongated members. Said first and second elongated members (1, 2) having ends (5, 6) which are pivotally connected to each other. The end (5, 6) of one of said first and said second elongated member (1, 2) is provided with at least two biased means (11, 12) adapted to be received in and interengaged with at least two sockets (13, 14) provided at the end (5, 6) of said other of the first and the second elongated member (1, 2). Said at least two biased means (11, 12) being displaced +0.05 to +1.0 degrees relative to an imaginary centre point, and a centre point of each of said at least two sockets (13, 14) being displaced -0.05 to - 1.0 degrees relative to an imaginary centre point, or vice versa, said imaginary centre points being aligned with each other.