Manufactured in Japan during the late 1950s and 1960s, the Makino K55 turret-type milling machines were produced by K.K.Makino Furaisu Seisakusho of 83 Nakane-cho, Meguro-ku, Tokyo. Makino has now, of course, moved away from conventional machine tools and is one of the leading exponents of CNC technology.
All models in the K55 range were of the ram-head "Bridgeport" type. Except for the KU-3 and KGU-3 die sinking models, all had a head that could be swivelled on its vertical axis 180° each way from central, moved through 300 mm of travel front to back and the head inclined 50° on each side of vertical
The range was divided into two types - High Speed and High Power - with each of these further divided into groups with and without power feed to the table, with and without power feed to the spindle and with and without optical measuring equipment - the latter being described (because of the accuracy of table positing available) as ""Commercial Jig Boring" types. A separate group was also offered, these being machines modified to carry 1D and 3D copying systems with the latter type also capable of die sinking.

High Speed Type
Model KB:  Main spindle manually controlled and with manual table feed
Model KBP:  Main spindle manually controlled and the table with power longitudinal feed

High Power Type
Model KG:  Main spindle manually controlled and with manual feed of the table
Model KGP:  Main spindle manually controlled and the table with power longitudinal feed

High Speed Type
Model KA: Power feed spindle and the table manually fed
Model KAP: Power feed spindle and the table with power longitudinal feed

High Power Type
Model KGA: Power feed spindle and manual feed of the table
Model KGAP:  Main spindle with power feed and the table with power longitudinal feed

Models with optical positioning equipment and listed as "Commercial Jig Boring" types included the:

High Speed Type
Model KJ: Optical positioning equipment, power feed spindle and manual feed of the table
Model KJP: Optical positioning equipment, power feed spindle and power longitudinal feed to the table

High Power Type
Model KGJ: Optical positioning equipment, power feed spindle and manual feed of the table
Model KGJP:  Optical positioning equipment, power feed spindle and power longitudinal feed to the table

By adding a 1D duplicating system the models became the:

High Speed Type
Model KC with 1D duplicating system and manual table feed
Model KCP with 1D duplicating system and power longitudinal feed
Model KJ-C  with 1D duplicating system, manual table feed and optical positioning equipment
Model KJP-C with 1D duplicating system, automatic longitudinal table feed and optical positioning equipment

High Power Types with a 1D duplicating system were also offered as the:
Models KGC, KGCP, KGJ-C, and KGJP-C were all fitted with 3D duplicating equipment.

With a 3D Duplicating system, the following were offered
Model KU-3  3D Universal Die-singing milling machine with High Speed Head
Model KGU-3 3D Universal Die-singing milling machine with High Power Head

Despite the variety of specifications offered, all models save the die-sinking KU-3 and KGU-3, had a 1100 x 250 mm table with three 14 mm T-slots, 550 mm of longitudinal travel, 250 mm in traverse and 350 mm vertically. As far as can be discovered, all High Speed heads were driven by a 0.75 kW motor and had ten spindle speeds of 225, 385, 450, 670, 770, 1155, 1340, 2000, 2310, and 4000 r.p.m.  High Power heads were fitted with a 2.5 kW motor, this being more than three times as powerful to give eight spindle speeds of 130, 195, 290, 440, 660, 935, 1480, and 2200 r.p.m.
While all the standard ram-head models had had twelve rates of table feed from 25 to 625 mm per minute, the 1D die-sinking machines (with either a High Power of High Speed head Models KGC, KGCP, KGJ-C, and KGJP-C)  had twelve rates of longitudinal power feed from 16.5 to 415 mm per minutes. Also different because of their special functions, the 3D Models (KU-3 and KGU-3), had a 1245 x 250 mm table with feed rates that varied continuously under hydraulic control from 0 to 500 mm/minute..