Based on the design of the well-established Deckel FP1 universal milling machine, the TOS FN22 was the start of a line of similar machines to be offered and first listed in 1952. Of ingenious construction, the miller had, on the front of the main column, a vertical table with 2 T-slots on which could be mounted a variety of both plain and swivelling tables and other attachments.
The layout of the spindle-drive system was both compact and effective: the top of the main column was machined as a slideway to carry a separate housing that doubled to mount a horizontal milling overarm and act as a base for various types of milling and slotting heads. By combining the various tables and heads - and utilising other accessories - a skilled technician was seldom defeated in his attempts to produce the most complex of milled and drilled components - and all to a very high standard of accuracy.
To solve the problem of how to drive the spindle when its housing was moved forwards and backwards (to provide lateral travel to the cutter), a long fixed gear was mounted parallel to and beneath it on the final-drive shaft and the upper gear allowed to slide along it.
Besides normal horizontal and vertical milling operations, a range of accessories was provided to cover slotting, jig boring, jig grinding, spiral milling and punch milling. In respect of these operations, an important part of the machine's versatility was dictated by the multi-angle, swivelling and tilting table; with just a plain table in place, the miller is still very desirable, but, without it, it is not possible to enjoy, in full, all the wonderful and versatile capabilities of this particular type.
Cleverly arranged so that the table-feed rates were completely independent of spindle speeds, the drive system began with a two-speed, 1.9.2.2 h.p. 1400/2800 r.p.m 3-phase motor mounted inside the main column. The table-feed gearbox was also mounted inside the column, below the spindle-drive gears, and had eight speeds; used in conjunction with the two-speed motor this arrangement gave 19 rates of longitudinal and vertical feed, both being from 8 to 500 mm per minute. Longitudinal table travel was 270 mm and the vertical 300 mm.
Fitted with a No. 4 Morse taper socket, the horizontal spindle had 16 speeds from 40 to 2000 r.p.m. There was, of course,  no table cross feed, this being provided by the head being moved in and out through a range of 150 mm by either a fine-feed handwheel or under power with a choice of 19 feed rates from 8 to 500 mm per minute..
Several types of vertical head and cutter supports were available: an overarm and drop bracket to hold a horizontal milling arbor (supplied as part of the standard equipment); a vertical head able to be swivelled 180° each side of upright with a No. 4 Morse taper nose, 80 mm of quill travel (by a hand-lever only) and 16 speeds from 40 to 4000 r.p.m.; a desirable high-speed vertical head with 65 mm of quill travel driven by its own motor through a V-belt to give speeds of 3150, 4000 and 5000 r.p.m., and a 360° swivelling slotting head with a ram stroke from 0 to 80 mm and stroke rates adjustable from 40 to 250 per minute. Unfortunately, none of the quill-feed heads had any form of fine downfeed by a handwheels, only a lever being provided. While the Deckel did have this feature, the handle was impossibly small and uncomfortable to use.
As important as the various heads, the tables provided included a fixed 220 x 650 mm type with four 12 mm T-slots on a spacing of 50 mm; a universal 260 x 640 table with five T-slots on 50 mm spacing that could be swivelled each way from horizontal by 45°, tilted front to back through 30° and rotated around its vertical axis by 45° each side from central; a large circular table was also listed, this being 360 mm in diameter with seven parallel 12 mm T-slots on 50 mm spacing and supplied complete with 3 division plates; the final offering was a very Deckel-like dividing attachment for direct and indirect dividing supplied with three division plates and able to be mounted on all the standard tables including the front vertical.
Although the range of accessories did not quite match that offered by Western makers of similar models - there being, for example, no specialised milling attachment for intricate corner work - this was a very substantially constructed (830 kg) precision miller offered at a price considerably below that of the competition.
A full specification sheet for the F22 can be found below.
Subsequent to the FN22, TOS, by the 1970s TOS had introduced a series of updated universal precision milling machines, the FN-20, FN-32 and FN40

*Proof of the this type of milling machine's success - the genus Precision Universal Milling Machine - is evident from the number of similar machines made in various countries including:
Austria:
Emco Model F3
Belgium:  S.A.B.C.A. Model JRC-2
Czechoslovakia:  TOS
England: Alexander "Master Toolmaker" and the Ajax "00", an import of uncertain origin.
Germany: Hahn & Kolb with their pre-WW2 Variomat model
Wilhelm Grupp Universal- Fräsmaschine Types WF1, UF 20 N/120 and others - some being sold as Mikron
Hermle Models UWF-700 and UWF-700-PH
Leinen Super Precision Micro Mill
Macmon Models M-100 & M-200 (though these were actually manufactured by Prvomajska); Maho (many models over several decades)
Ruhla
Rumag Models RW-416 and RW-416-VG
SHW (Schwabische Huttenwerke) Models UF1, UF2 and UF3
Thiel Models 58, 158 and 159
Wemas Type WMS
Italy: C.B.Ferrari Models M1R & M2R
Bandini Model FA-1/CB and badged as Fragola (agents, who also sold a version of the Spanish Meteba).
Di Palo (Early, very Deckel-FP1-like with later production including much bigger and heavier models including the Type DFF.2)
Japan: Riken Models RTM2, a copy of the FP1 and the RTM3, a copy of the Deckel FP2. These machines, made from the late 1950s until the end of the 1980s, were slowly developed and improved, are beautifully constructed and have simple, reliable electrical systems.
Poland: "Avia" and "Polamco" Models FNC25, FND-25 and FND-32 by Fabryka Obrabiarek Precyzyinych
Romanian branded for sale in the UK as the "Infratirea"?
Russia: "Stankoimport 676"
Spain: Metba Models MB-0, MB-1, MB-2, MB-3 and MB-4
Switzerland: Aciera Models F1, F2, F3, F4 and F5
Christen and Perrin Types U-O and U-1 (Perrin Frères SA, Moutier)
Hispano-Suiza S.A. Model HSS-143
Luthy
Mikron Models WF2/3S, WF3S, WF-3-DCM & WF-2/3-DCM
Perrin Type U-1
Schaublin Model 13 and Model 22
Schaffner Type 25
The former Yugoslavia: Prvomajska (in Zagreb with Models ALG-100 and ALG200)
Sinn Models MS2D & MS4D
"Comet" Model X8130, imported to the UK in the 1970s by TI Comet.
United States: Brown & Sharpe "Omniversal"
Sloane & Chace in the USA produced a miniature bench version and at least five Chinese-built models have also been made, including one from the Beijing Instrument Machine Tool Works. A number of the "clones" merely followed the general Thiel/Maho/Deckel concept whilst others, like Bandini and Christen, borrowed heavily from Deckel and even had parts that were interchangeable. Should you come across any of these makes and models all will provide "The Deckel Experience" - though you must bear in mind that spares are unlikely to be available and, being complex, finely-made mechanisms, they can be difficult and expensive to repair..