cannot be added subsequently to profiles that are closed at the end.

The nuts for T-slots must be pushed in from the end of the groove.

can be inserted in the groove anywhere required. This is optimal for assemblies on existing constructions. Rhombus and T-head nuts have this property. This also applies to T-head bolts. Insertion aids are useful for this type of nuts for T-slots, e.g. slot in the slot nut, thread with pitch error, marking or plastic follower in the thread. 

can be inserted in the groove anywhere required. This is optimal for assemblies on existing constructions. Rhombus and T-head nuts have this property. This also applies to T-head bolts. Insertion aids are useful for this type of nuts for T-slots, e.g. slot in the slot nut, thread with pitch error, marking or plastic follower in the thread. 

generally result in greater positioning tolerance for the thread hole. This depends on the difference between the dimension b of the width of the slot nut and dimension B of the slot base width of the mounting rail.

This symbol indicates the slot base width B in the mounting rail (C-rail).

The flange width (dimension a) of this nut for T-slots is chosen so that sufficient clearance remains between the slot nut and the groove, dimension A. Dimension a is chosen so that a sufficiently precise positioning tolerance results for the thread hole.

This symbol indicates the groove width A.