WCO Explanatory Notes reproduced for reference. © World Customs Organization. Verify against official WCO publication.
84.57 - M a c h i i g centres, unit construction machines (single station) and multi-station transfer machines, for working metal. 8457.10 - Machining centres 8457.20 - Unit construction machines (single station) 8457.30 - Multi-station transfer machines I This heading applies (see Note 4 to this Chapter only to machine-tools for working metal (other than lathes (including turning centres)) whic can carry out different types of machining operations on a single workpiece either : (a) by automatic tool change from a magazine or the like in conformity with a machining programme (machining centres); (b) b the automatic use, simultaneously or sequentially, of different unit heads working on a z e d position workpiece (unit construction machines, single station); or (c) by the automatic transfer of the workpiece to different unit heads (multi-station transfer machines). (A) MACHINING CENTRES Machining centres are individual machines, i.e., all the machining operations are pe~ormedon a single (multi-function) machine. These centres must satis5 two conditions : they must carry out several machining operations and they must have automahc tool change, from a magazine or the like in conformity mth a machining programme. Consequently, this group covers machine-tools which c out two or more machinin operations by automatic tool change from a ma mine or the li e, whereas machine-tools whic carry out one machining operation using a sing e tool or several tools working simultaneously or se uentially (for exam le, multi le-spindle drills or multiple-cutter milling machines) are classi led in headings 84. 9 to 84.6f 9. S f f The automatic tool chan e re uirement excludes from the heading multi-function machines (for example, machines and mill) in which the various tools are not changed automatically. Such in headings 84.59 to 84.61 in accordance with Note 3 to Section XVI or by application of Interpretative Rule 3 (c) unless, of course, they can be re arded as multi-station transfer machines, in which the workpiece is automatically trans erred to the different unit heads (see Part (C) below). ? Machining centres may also include auxiliary devices such as pallet changers, systems of pallet magazines or tool magazine changers. (B) UNIT CONSTRUCTION MACHINES (SINGLE STATION) Unit construction (single station) machines are multi-function machines in which the workpiece is held in a fixed position while the unit heads move relative to the workpiece to carry out the operation or the machine operations. The unit heads are parts of the machines on which they are mounted and are used to hold, guide and actuate (rotate, advance, retract) the interchangeable tool. Rotating heads usually incorporate an electric motor, while translation heads usually incorporate a hydraulic cylinder : these two types of head may be combined. This group covers unit construction machines (sin e station) carrying out two or more machining operations with the use of two or more unit eads. f However, machines carrying out one machining operation with the use of several unit heads or those carrying out several machining operations with the use of a single unit head are excluded. (C) MULTI-STATION TRANSFER MACHINES The machines of this group must satisfy three conditions : they must .carry out several machining operations, they must work by the automatic transfer of the workpiece to the tool and they must be equipped with various unit heads. A distinction is generally made between rotary transfer machines and linear transfer machines. In the former, the unit heads which perform the various operations are arranged in a circle on a common base. The workpiece travels around the circle in such a way that, at each stop (station), it is worked on by the tools of the correspondin unit head (for example, drilling, boring, tap ing). In linear transfer machines, the unit hea s are arranged in a line on a common base an work successively on the workpiece as it travels from one head to another, along the line. d B In accordance with Chapter Note 4 (c) this heading does not cover transfer lines consisting of various machines linked by a conveyor carrying the workpieces. Under the terms of the above-mentioned Chapter Note, this headin also excludes "flexible manufacturing systems " (FMS)which consist of several machines, general y numerically controlled, or several groups of machines, together with automatic handling facilities such as lifting fiames, conveyors, unmanned trolleys, manipulators and industrial robots, for conveying the wor ieces to the machines or removing them after machining. The various groups of machlnes and the andljng facilities which constitute the flexible manufacturing system are controlled by automatic data processing machines. f % PARTS AND ACCESSORIES Sub'ect to the general provisions regarding the classification of arts (see the General Exp anatory Note to Section XVI), parts and accessories (other than t e tools of Chapter 82) of the machine-tools of this heading are classified in heading 84.66. K The heading also excludes : (a) Machine-tools for working an material, by removal of material, by laser or other light or photon beam, ultrasonic, electro-disc arge, electro-chemical, electron beam, ionic beam or plasma arc processes; water-jet cutting machines (heading 84.56). K (b) Lathes (including turning centres) for removing metal (heading 84.58). (c) Way-type unit head machines (heading 84.59). (d) Soldering, brazing or welding machines and apparatus of headings 84.68 and 85.15. -
1.- This Chapter does not cover : (a) Millstones, grindstones or other articles of Chapter 68; (b) Machinery or appliances (for example, pumps) of ceramic material and ceramic parts of machinery or appliances of any material (Chapter 69); (c) Laboratory glassware (heading 70.17); machinery, appliances or other articles for technical uses or parts thereof, of glass (heading 70.19 or 70.20); (d) Articles of heading 73.21 or 73.22 or similar articles of other base metals (Chapters 74 to 76 or 78 to 81); (e) Vacuum cleaners of heading 85.08; (f) Electro-mechanical domestic appliances of heading 85.09; digital cameras of heading 85.25; (g) Radiators for the articles of Section XVII; or (h) Hand-operated mechanical floor sweepers, not motorised (heading 96.03). 2.- Subject to the operation of Note 3 to Section XVI and subject to Note 11 to this Chapter, a machine or appliance which answers to a description in one or more of the headings 84.01 to 84.24, or heading 84.86 and at the same time to a description in one or more of the headings 84.25 to 84.80 is to be classified under the appropriate heading of the former group or under heading 84.86, as the case may be, and not the latter group. (A) Heading 84.19 does not, however, cover : (i) Germination plant, incubators or brooders (heading 84.36); (ii) Grain dampening machines (heading 84.37); (iii) Diffusing apparatus for sugar juice extraction (heading 84.38);