WCO Explanatory Notes reproduced for reference. © World Customs Organization. Verify against official WCO publication.
38.10 - Pickling preparations for metal surfaces; fluxes and other auxiliary preparations for soldering, brazing or welding; soldering, brazing or welding powders and pastes consistin of metal and other materials; preparations of a kind used as cores or coatings or welding electrodes or rods. f 38 10.10 - Pickling preparations for metal surfaces; soldering, brazing or welding powders and pastes consisting of metal and other materials 3810.90 - Other (1) Pickling preparations for metal surfaces. These are preparations used to remove oxides, scale, rust or tarnish from the surface of metals, or for rou ,ening these surfaces to facilitate certain o erations. The picklin process may be a finis ing o eration, or may be effected at an ear ler stage (to prepare &e metal far drawing or extru ing operations, for example , or prior to coating the metal, e.g., by galvanising, metallising, tinnmg, cladding, electrop ating, painting, etc. f S. P Pickling preparations are usually based on dilute acids (h drochloric, sulphuric, hydmfluoric, nitric, phosphoric, etc.), and sometimes contain inhi&tors which restrict the corrosion of the metal. Some, however, have a basis of alkalis (e.g., sodium hydroxide). The heading does not include cleaning preparations for metals (heading 34.02). (2) Fluxes and other auxiliary pre arations for soldering, brazing or welding. Fluxes are used to facilitate the joining o f tYle metals in the rocess of solderin ,brazin or welding, by protecting the metal surfaces to be oined an the solder itself i$om oxi ation. They have the property of dissolving the oxi e which forms during the operation. Zinc chloride, ammonium chloride, sodium tetraborate, rosin and lanolin are the products most commonly used in these preparations. B Fi % This group also includes mixtures of aluminium granules or owder with various metallic oxides (e.g., iron oxide) used as interne heat-generators {lmino-thermic process) in welding operations, etc. (3) Soldering, brazing or welding powders and astes consisting of metal and other materials. These preparations are used to makeht! e metal surfaces to be joined adhere to each other. Their essential constituent is metal (usually alloys contaming tin, lead, copper, etc.). These preparations are classified in the heading only when : (a) They contain other constituents as well as metals. These constituents are the auxiliary preparations described in (2) above; and (b) They are put up in the form of powders or pastes. Soldering, brazing or welding reparations consistin solely of metallic powders, whether or not mixed together, are excluded ( hapter 71 or ~ e d i o n according b to ther constituents). (4) Preparations of a kind used as cores or coatin for welding electrodes or rods. These are mainly intended to eliminate, in the form of I!? sible slag, the oxides which form during welding operations. They usually consist of a refractory mixture containing, for example, lime and kaolin. Electrodes, of base metal or of metal carbides, coated or cored with a flux, are excluded (heading 83.11).
1.- This Chapter does not cover : (a) Separate chemically defined elements or compounds with the exception of the following : (1) Artificial graphite (heading 38.01); (2) Insecticides, rodenticides, fungicides, herbicides, anti-sprouting products and plant-growth regulators, disinfectants and similar products, put up as described in heading 38.08; (3) Products put up as charges for fire-extinguishers or put up in fire-extinguishing grenades (heading 38.13); (4) Certified reference materials specified in Note 2 below; (5) Products specified in Note 3 (a) or 3 (c) below; (b) Mixtures of chemicals with foodstuffs or other substances with nutritive value, of a kind used in the preparation of human foodstuffs (generally heading 21.06); (c) Products of heading 24.04; (d) Slag, ash and residues (including sludges, other than sewage sludge), containing metals, arsenic or their mixtures and meeting the requirements of Note 3 (a) or 3 (b) to Chapter 26 (heading 26.20); (e) Medicaments (heading 30.03 or 30.04); or (f) Spent catalysts of a kind used for the extraction of base metals or for the manufacture of chemical compounds of base metals (heading 26.20), spent catalysts of a kind used principally for the recovery of precious metal (heading 71.12) or catalysts consisting of metals or metal alloys in the form of, for example, finely divided powder or woven gauze (Section XIV or XV). 2.- (A) For the purpose of heading 38.22, the expression “certified reference materials” means reference materials which are accompanied by a certificate which indicates the values of the certified properties, the methods used to determine these values and the degree of certainty associated with each value and which are suitable for analytical, calibrating or referencing purposes. (B) With the exception of the products of Chapter 28 or 29, for the classification of certified reference materials, heading 38.22 shall take precedence over any other heading in the Nomenclature. 3.- Heading 38.24 includes the following goods which are not to be classified in any other heading of the Nomenclature : (a) Cultured crystals (other than optical elements) weighing not less than 2.5 g each, of magnesium oxide or of the halides of the alkali or alkaline-earth metals; (b) Fusel oil; Dippel's oil; (c) Ink removers put up in packings for retail sale; (d) Stencil correctors, other correcting fluids and correction tapes (other than those of heading 96.12), put up in packings for retail sale; and (e) Ceramic firing testers, fusible (for example, Seger cones). 4.- Throughout the Nomenclature, “municipal waste” means waste of a kind collected from households, hotels, restaurants, hospitals, shops, offices, etc., road and pavement sweepings, as well as construction and demolition waste. Municipal waste generally contains a large variety of materials such as plastics, rubber, wood, paper, textiles, glass, metals, food materials, broken furniture and other damaged or discarded articles. The term “municipal waste”, however, does not cover : (a) Individual materials or articles segregated from the waste, for example wastes of plastics, rubber, wood, paper, textiles, glass or metals, electrical and electronic waste and scrap (including spent batteries) which fall in their appropriate headings of the Nomenclature; (b) Industrial waste;