Base plate clamp mountings GN 473 have a horizontal and a vertical clamping bore. The vertical clamping bore is additionally fitted with a square. The bore distance m of the base plate clamp mountings GN 473 is matched with the clamp mountings GN 477 and the flanged bolts GN 480 as well as retaining magnets GN 51.6. The standard version of the clamping screw is a socket cap screw with hexagonal socket DIN 912. It can be replaced by an adjustable clamping lever GN 511 (see table of dimensions).