To install the tip-up seats in the Nobina ST15 busses ourselves, FTBCI has sent us bolts. These bolts are M8x100 (Q150B08100-N) and have a thread length of 24 mm. While installing these we noticed that the thread does not seem to properly reach the tapping plate.The technical drawings (as seen below) confirm this problem, the bolt does not properly reach the tapping plate with its 24 mm thread and therefore the tip up seat does not have enough support.