This slot nut / fitting M6 or M8 can be used for the seat rail with airline profile in the Mercedes Benz V-Class, the Vito or the Viano – series 639 (second generation, 2003–2014) & 447 (third generation, since 2014).

The slot nut is inserted into the holes in the seat rail and moved in the grid so that the red centring disc can be inserted. It thus has a form fit with the rail to prevent slipping. Optimum holding force is ensured by the slot nut resting against four lugs of the seat rail. If there is a protective rubber over the rail, this must be pressed to the side when inserting, one side at a time – not both at once.

When not in use, the slot nut does not protrude above the seat rail and can additionally be braced with the rail by means of a threaded pin located in the lower part of the block, so that no rattling noises occur while driving.

Items such as camping equipment, tool boxes, dog boxes, bike racks or similar can be mounted on the rail.

Please note that the slot nut cannot be used at the fastening points of the track.

Note: The slot nut only fits the above vehicles and does not fit a standard airline track.

Please note the payload of the rail, as this may be lower than the payload of the slot nuts. The maximum tensile load of the seat rail can be found in the installation guidelines of the vehicle manufacturer. It is more likely that the rail will give way before the slot nut reaches its load limit. To ensure the specified payload, the corresponding fastening screw must be screwed into the slot nut at least 15 mm deep.

You can get to the two slot nuts here directly under the blog post.