A bolt of major diameter 12mm is required to clamp two steel plates. Cross sectional area of the threaded portion of the bolt is 84.3 mm2. The length of the threaded portion in grip is 30 mm, while the length of the unthreaded portion in grip is 8mm. Young’s modulus of material is 200 GPa. The effective stiffness (in MN/m) of the bolt in the clamped zone is _________