Hello. More or less I know about ball screw, but I am defenitly uncomprehending with type of ball nuts like this.

I guess that
S - single
D - double


| FSU | FSI | FDU | FDI | RSU | FSE | FSC | RSW | FSW | FDW | FSK |

I have checked on a drawing the number of holls, flange edges dia's but haven't found difference.

Where can I read about ball nuts?

P.S
Even in this, very useful article http://www.designworldonline.com/art...ew-Drives.aspx isn't mention about abbreviation

Thank you in advance.