Hello guys I m building a CNC for the first time and have some basic questions. I plan to use 10mm or 12mm diameter Lead screw.

1. Whats the pitch (in mm) or TPI generally used for hobby CNCs? After some research I see many ppl using 10 TPI (0.1" / 2.54mm pitch) lead screws... am I correct ? Does Higher TPI or Pitch decrease the accuracy ?

2. What sort of bearings can I use to hold the lead screw in place at both ends? Will 12mm ID bearing (rotary) work perfect ?

3. As per Nema 23 standard the shaft diameter is 1/4" or 6.35mm in metric. What kind of coupler can I use to couple the 6.35mm shaft to 12mm Lead Screw?

Can some one list the standard sizes in Imperial and Metric system for lead screws and bearings which are used for CNCs ?