The Threading Chart below is for Atlas lathes with the reverse lever in a gear box on the left-hand side of the leadscrew, and for which the gears engage the spindle gear only (ones with 96 tooth gears included with loose gears).

B = BACK POSITION (TOWARD HEADSTOCK)         F = FRONT POSITION (AWAY FROM HEADSTOCK)

I = IDLER GEAR                                                                S = SPACER GEAR

XXS = STEEL SPACER                                                      --- = BLANK