Sometimes badged as the AB Skania  and also Eskilstuna Tools (and with  examples of the latter often lacking a serial number) the superbly made Arboga UM400 was designed as a miniature multi-purpose machine tool able to perform vertical and horizontal milling, drilling, slotting, shaping, filing, grinding and simple lathe work. It achieved these objectives not by being able to reposition or adapt its major components, but rather by the addition of specific modules, each adapted to a single task. The machine's base unit was a bench-mounting 12" x 57/8" (280 mm x 150 mm) cast-iron foot together with a column to which was fitted a single T-slot 14" x 57/8" (360 mm x 150mm) table that had a longitudinal travel of 7 1/2" (190 mm), a cross feed of 23/4" (70 mm) and a vertical movement of 31/8" (80 mm). Micrometer-graduated collars were fitted to the feed screws and calibrated in either inch or metric graduations.
Driven by a 50 Hz 2-speed 3-phase 0.25/0.15 h.p. 2770/1410 rpm motor spindle speeds were: 365, 730, 1410 and 2770 r.p.m. For the American market a 60 Hz motor gave speeds of 440, 885, 1700 and 3400 r.p.m.
In order to create the main vertical miller a simple column (Part No. 4002) was dropped into a socket on the base (4001) and a right-angle column clamp (4003) fitted on top to hold the combined motor and spindle unit (4004).
Further details and pictures here and here.