A lathe introduced during the 1980s, the TOS SU-40 was one of a series of SU lathes made from the 1970s onwards. With a centre height of 200 mm the lathe could be had with a choice of three between-centre distances: 1000, 1500 and 2000 mm. Each version was able to take a load, held on centres, of up to 400 kg at the slowest spindle speed.
With a bore of 56 mm, the headstock spindle - case hardened and ground - ran in a double-row radial roller bearing at the front and in a pair of matched and preloaded angular contact ball races at the rear- all lubricated by grease.
Power came from a 3-phase, 7.5 kW, 1400 r.p.m. motor mounted on sliding rails to allow adjustment of the V-belts that took drive to the speed-change gearbox. The drive passed, as on most TOS lathes through two multi-plate clutches - these doubling to act as a spindle brake. The drive arrangement gave a most useful range of 18 spindle speeds from 14 to 2240 r.p.m.
The screwcutting and feeds gearbox, totally enclosed against the ingress of dirt and turnings, provided 48 longitudinal rates of carriage feed from 0.06 to 6.4 mm/min - and 48 in cross-feed from 0.03 to 3.2 mm/min.
Screwcutting was arranged to provide 45 Metric pitches from 0.5 to 60 mm; 56 Whitworth ( inch) pitches from 1/16 to 60 t.p.i. and 32 Module from MD 0.125 to 15.
The SUI-32 weighed when specified with 750 mm between centres, approximately 1460 kg. 
The full specification - and details of the various options - can be found below.