Still operating successfully today, the Tsugami Mfg. Co. Ltd had, during the 1960s and 1970s, its head office at 4-1-10 Shimbashi, Minato-ku in Tokyo. The Company was founded in June 1923, a time when, although capable of manufacturing complex mechanical items, Japan lacked one vital resource, the ability to produce ultra-high precision measuring equipment. Without a home-based industry of such items as micrometers and the essential Johansson block gauges, Japan had to rely upon expensive imports, thus limiting the extent to which smaller engineering firms could improve the quality of their products. Research into the making of block gauges was started at Honjo Ohira-cho in Tokyo, in 1923 and, no doubt in association with the Mitsui Company who were also engaged in similar work, by March 1937 production of block gauges had started in Nagaoka-shi, in the Niigata prefecture. Now armed with the precision measuring equipment needed, by June 1939, production of the Tsugami L-type thread milling machine Model T-TML500 was underway alongside a hydraulic universal cylindrical grinder, the Model T- UG300.
By the 1960s, the Company's two smallest grinders were the T-CGD cylindrical and T-IGD internal, both small, self-contained and compact machines intended for very high precision work. Depending upon the material being ground, the makers claimed roundness could be achieved to a few 10 thousandths of a millimetre (one-100 thousandth of an inch) and surface texture to several 100 thousands of an inch (under one micro inch US method) - with both determined using English-made Taylor Hobson Talyrond  and Talysurf machines.
T-CGD
Able to take work with a minimum diameter of 0.8 mm (1/8") to a maximum of 35 mm (1 3/8") - and a length of up to 150 mm (529/32") - the T-CGD had five workhead spindle speeds of 190, 310, 515, 850 and 1400 r.p.m. driven by a 1/4 h.p., 15000 r.p.m. 50-cycle motor. Using a 1/6 h.p. 3000 r.p.m. 50-cycle motor, the wheelhead had two speeds of 5000 and 6,000 r.p.m. (motor speeds are quoted for a 50-cycle supply)
Two workheads were available for the T-CGD; fitted as standard was a 'centre' type intended to be used with a tailstock for between-centres' work with, as an alternative at extra cost,  a 'chucking' model that sat on a base able to be swivelled 90° in either direction from central. This head could take 3-jaw chucks or collets, the latter held with a drawtube or, for an additional charge, a lever-action closer. A choice of two high-precision 3-jaw chucks was offered, one with a maximum capacity of 25 mm (1") and the other able to hold work up to 50 mm (2") in diameter with collets provided in sets to take work from 0.5 mm to 6 mm.
The wheelhead sat on base able to be swivelled 90° in either direction from central and had an in-and-out travel of 30 mm (13/16"). It could be moved by hand or indexed automatically under power with the infeed able to take place at either end of the table's stroke. The amount of stock to be removed was set by a scale - graduated in divisions of 0.002 mm (or 0.0001") on the upper section of the infeed handwheel.  The amount of stock to be removed per pass was set by an infeed dial, set beneath the infeed adjusting lever - this reading to a minimum setting of 0.001 mm (0.00005").   
Able to be reciprocated by either hand or automatically under power (the changeover from one to the other being by a lever) the table had a maximum travel of 150 mm (529/32"). When under power, three rates of feed were provided spanning 50 to 1120 mm/min (2" to 44") - these being changed by moving a flat belt across a three-step pulley within the cabinet stand. Under power, the table feed was reduced from its maxium of 150 mm by hand to 80 mm ( 35/32") - with 10mm (3.8") being the minimum travel able to be set. To limit table travel, two standard stops were fitted together with two micrometer-adjustable ones, these being graduated with divisions of 0.05 mm (0.001"). Sitting on top of the sliding table was the work-holding table, this able to be swivelled by up to plus or minus 4.5° to allow the turning of shallow tapers.
A conversion kit was also available for the T-CGD to convert it for internal grinding.
T-IGD
Using the same base unit as the T-CDG, the T-IGD was able to take work with a minimum diameter of 8 mm (5/16") to a maximum of 12 mm (15/32") the T-IGD had five workhead spindle speeds of 190, 310, 515, 850 and 1400 r.p.m. driven by a 1/4 h.p., 15,000 r.p.m. motor. Using a 1/6 h.p. 3000 r.p.m. motor, the wheelhead had two speeds of 32,000 and 60,000 r.p.m. (motor speeds are quoted for a 5-cycle supply).
Although the wheel spindle fitted to the T-CGD was the same for both the 5000 r.p.m. and 6000 r.p.m. versions, due to the very high speeds required for internal grinding, the makers offered three different spindles to cover the various speeds needed on jobs with different internal diameters and depths. For very small jobs, the Spindle Type TD-50-60 was fitted with an oil-mist lubrication system and was intended for use work with bores from 3 to 9 mm and depths from 10 to 20 mm. With grease lubrication, the Spindle Type TD50-60A covered jobs with  bores from 5.5 mm to 12 mm and depths from 18 to 23 mm. Also grease-lubricated, the Spindle TD50-32A was designed for bores from 8 to 22 mm and depths from 25 to 55 mm.
Oil mist lubrication of the bearings required a special, extra-cost, stand-alone unit beside the grinder that needed coupling to a customer-installed air compressor of around 1/4 h.p. To special order, an internal grinding spindle capable of running at 120,000 r.p.m. could be provided - this also, of course, required oil-mist lubrication.
Sitting on a base able to be swivelled 90° in either direction from central, the wheelhead had a travel of 30 mm (13/16") and could be moved by hand or indexed automatically under power. In the latter setting the infeed could take place at either end of the table stroke with the amount of stock to be removed set by scale on the upper section of the infeed handwheel graduated in divisions of 0.002 mm (or 0.0001" on the inch model). The amount of stock removed per pass was set by an infeed dial, set beneath the infeed adjusting lever, that read to a minimum of 0.001 mm (0.00005").   
The table could be reciprocated by either hand or automatically under power and, by hand, had a maximum travel of 150 mm (529/32"). To limit its travel, two standard table stoppers were fitted together with two micrometer-adjustable stoppers graduated with divisions of 0.05 mm (0.001"). Sitting on top of the sliding table was the work-holding table, this able to be swivelled by up to plus or minus 4.5° to allow the turning of shallow tapers. When travelling under power, three rates of feed were provided spanning 110 to 2700 mm/min (4" to 107") - these being changed by moving a flat belt across a three-step pulley within the cabinet stand. When used under power, the table feed was reduced from its maxiumum of 150 mm by hand to 80 mm ( 35/32") - with a minimum travel of 10 mm (3/8").
Both grinders were fitted with a coolant supply fitted inside the cabinat stand with a centrifugal pump and the necessary piping - though, rather oddly, the delivery nozzle was charged extra. Also at addition expencet, a magnetic filter could be fitted to better clean the fluid.
With a floor area of 1250 x 985 mm (49" x 39") the net weight of both models was 480 kg (1060 lbs).
In 1969 the two grinders were listed in the UK at £2070 including import duty, an amount equal, in 2024, to £43,000.