T-nuts are as the title says, a nut with a “T” cross-section. This means they can be used in a T-slot for retaining and fixing parts.
The T-nut fits in a T-slot and so has to be made to certain dimensions.
Below I have labelled the dimensions of a T-nut and in the table I have given some of the common sizes.
|Slot Size B [mm]||Thread A||C [mm]||D [mm]||E [mm]||F [mm]|
|8||M6 x 1.0||10||6||14||19|
|10||M6 x 1.0||11||6||16||22|
|10||M8 x 1.25||11||6||16||22|
|12||M10 x 1.5||13||7||17||22|
|14||M10 x 1.5||16||9||22||29|
|14||M12 x 1.75||16||9||22||29|
|16||M12 x 1.75||16||9||25||29|
|18||M16 x 2.0||19||11||29||32|
|20||M16 x 2.0||25||14||32||38|
|22||M20 x 2.5||25||14||35||38|
|27||M24 x 3.0||29||18||41||51|
I have found that in the model making arena the T-nut dimensions are not that accurately followed. Sometimes a mix of T-nuts and threads is actually rather useful.
Double T-nuts that I made from mild steel for my low profile vice project.
These are 12mm T-nuts and I have threaded them for 6mm and 8mm.
Long T-nuts that I made to extend the working diameter of the rotary table.