What type of leadscrew is this please

[weiry]

Hi
I have been trying to find information on this leadscrew, so far I know the following
Material: Stainless steel lead screw, copper nut
Screw diameter: 8mm
Length: 295mm
Screw spacing: 2mm
Lead of thread: 8mm

But my problem is, I would like to know how to visually see the starts os it single or double, how can I tell. Also I counted the threads and it has 13 threads per inch but when I go the the Prusa calculator there doesn't seem to be the right numbers to choose from.

I really appreciate the help anyone might be able to give me.

Regards weiry

[jjpython]

Look at the end of the screw and count the ridges

[alan richard]

TR8x2 perhaps. Single start would have just one groove running around it.

[james_i]

Looks like an acme thread to me ,to find out single or twin start run the nut to the end push down and turn it if you feel two bumps per Revolution it's a twin one bump it's a single.