What's your rule of thumb for number of loose tenons?

[el_Pedr0]

When joining with loose tenons, what's your rule of thumb for the number of loose tenons you'll place in one joint?

In other words, I'm looking for realistic numbers to put in the table below - I've just stuck any old numbers in for now.

Assume 18mm MDF, standard kitchen carcass type construction.

Number of loose tenons	Joint width
1	50mm - 100mm
2	100mm - 500mm
3	500mm-1000mm

 

[Distinterior]

Assuming the cabinets you're constructing are " standard " sizes, then base and tall units will be 560/570mm deep and wall units would be anywhere from 300 to 350mm deep.
I use 5mm Dominos for my loose tenons ( with 18mm thick material) and would have 5 per joint on my base & tall units.
2 per joint on my top front & rear rails.
3 or 4 per joint on my wall units, depending on the chosen depth of the cabinets.

 

[el_Pedr0]

I sometimes do some non standard dimensions. In particular the rails get a bit narrow. How narrow before it only gets to one domino? Is it simply a case of whether 2 will fit? Do you ever bring your domino closer than 37mm to the edge?

 

[Hornbeam]

Do you ever bring your domino closer than 37mm to the edge?

Regularly, more often when I am replacing a conventional M+T joint and sometimes as close as 5mm

 

[Distinterior]

Do you ever bring your domino closer than 37mm to the edge?

Rarely, if it's a manmade board of material.....Solid timber, as Horbeam stated, I will mortice closer to the edge.