The AV, AVI and AVII Lorch plain-turning lathes all had the same length of bed and centre height but were fitted with different headstock spindles having bores of  0.63" (16 mm) , 0.78" (20 mm) and  1.3125" (33 mm) to accept, respectively, collets with maximum through bores of:  0.39" (10 mm),  0.656" (16.5 mm) and  1.0625" (27 mm).
The headstock spindle was completely hardened and ran in adjustable, hard bronze bearings. The ball-bearing spindle-thrust race was completely covered and a simple draw-in collet holding system was fitted as standard. Because the larger bore spindles necessitated slightly different headstock casting, the between-centres of capacity of the larger variants was reduced from the 13 inches of the basic Model AV to 12.25" for the AVI - and 11.5" for the AVII.
The compound slide rest was the same for all models and had a longitudinal travel of 5.3" (135mm) and a cross movement of 6" (150 mm)

Model AVI fitted with the heavier headstock and also equipped with a Chase-type threading attachment. The latter device could be fitted to all but the smallest of the Lorch Precision Instrument and Toolmaker's lathes.