Nickel and articles thereof Note. 1.- In this Chapter the following expressions have the meanings hereby assigned to them : (a) Bars and rods Rolled, extruded, drawn or forged products, not in coils, which have a uniform solid cross-section along their whole length in the shape of circles, ovals, rectan les (including s uares), equilateral trim les or regular convex polygons (including " flattened circyes " and "modi ed rectangles ", of whic! two op osite sides are convex arcs, the other two sides being straight, of equal length and arallel). Pro ucts with a rectangular (including square), triangular or polygonal cross-section may ! h e corners rounded alon their whole length. The thickness of such products which have a rectangular including " moiified rectangular ") cross-section exceeds one-tenth of the width. The expression so covers cast or sintered products, of the same forms and hmensions, which have been subsequently worked after production (otherwise than by simple trimming or de-scaling), rovided that they have not thereby assumed the character of articles or products of other Eeadings. a LS Rolled, extruded, drawn, for ed or formed products, coiled or not, of a uniform cross-section along their whole len th, which tfo not o o h to an of the dehitions of bars, rods, wire,plates, sheets, i*, foif tubes or ipes. The expression arso covers cast or sintered products, of the same forms, whch have been sugsequently worked af'ter production (otherwise than by simple trimming or de-scaling), provided that they have not thereby assumed the character of art~clesor products of other headings. (c) Wire Rolled, extruded or drawn products, in coils, which have a uniform solid cross-section along their whole length in the shape of circles, ovals, rectangles (including s uares), equilateral triangles or regular convex polygons (including flattened circles " and '' modlied rectan Ies ",of which two opposite sides are convex arcs, the other two sides being straight, of equal ength and parallel). Products with a rectan lar including s uare), triangular or poly onal cross-section may have comers rounded along t r eir w ole length. The thickness of such pr08ucts which have a rectangular (including " modified rectangular ") cross-section exceeds one-tenth of the width. k i (d)Plates, sheets, strip and foil Plat-surfaced products (other than the unwrought products of heading 75.02), coiled or not, of solid rectangular other than s uare) cross-section with or without rounded corners (including " modifie rectan les " o whlch two op osite sides are convex arcs, the other two sides being stra~ght,of equal l e n d and parallel) of a uniyonn thickness, which are : - of rectangular (including square) shape with a thickness not exceeding one-tenth of the width, - of a shape other than rectangular or square, of any size, provided that they do not assume the character of articles or products of other headings. Heading 75.06 applies, inter alia, to plates, sheets, strip and foil with patterns (for example, grooves, ribs, chequers, tears, buttons, lozenges) and to such products which have been perforated, corrugated, polished or coated, provided that they do not thereby assume the character of articles or products of other headings. (e) Tubes and pipes Hollow products, coiled or not, which have a uniform cross-section with only one enclosg void along their whole length in the shape of circles, ovals, rectangles (including squares), equilateral triangles or regular convex polygons, and which have a uniform wall thickness. Products with a rectangular (including square), equilateral triangular, or regular convex polygonal cross-section, which may have comers rounded along their whole length, are also to be considered as tubes and pipes provided the inner and outer cross-sections are concentric and have the same form and onentation. Tubes and pipes of the fore oing cross-sections may be olished, coated, bent, threaded, drilled, waisted, expanded, cone-s aped or fitted with flanges, co ars or rings. H t Subheading Notes. 1.- In this Chapter the following expressions have the meanings hereby assigned to them : (a) Nickel, not alloyed Metal containing by weight at least 99 % of nickel plus cobalt, provided that : (i) the cobalt content by weight does not exceed 1.5 %, and (ii) the content by weight of any other element does not exceed the limit specified in the following table : TABLE - Other elements Element Limiting content % by weight Fe Iron 0.5 Oxygen 0.4 0.3 Other elements, each (b)Nickel alloys Metallic substances in which nickel predominates by weight over each of the other elements provided that : (i) the content by weight of cobalt exceeds 1.5 %, (ii) the content by weight of at least one of the other elements is greater than the limit specified in the foregoing table, or (iii) the total content by weight of elements other than nickel plus cobalt exceeds 1 %. 2.- Notwithstanding the provisions of Chapter Note 1 (c), for the urposes of subheading 7508.10 the term " wire ".applies only to products, whether or not in coils, o any cross-sectional shape, of which no cross-sechonal dimension exceeds 6 mrn. r! GENERAL This Chapter covers nickel and its alloys, and certain articles thereof. Nickel is a relatively hard, greyish-white metal melting at 1453 "C.It is ferro-magnetic, malleable, ductile, strong and resistant to corrosion and oxidation. Nickel is used maid in the production of many alloys especially alloy steels, for coating other metals usually by e ectrodeposition and as a catalyst in many chemical reactions. Unalloyed wrought nickel is also extensively used in the manufacture of chemical plant. In addition nickel and nickel alloys are used for coinage. The princi a1 nickel alloys which may fall in this Chapter under the provisions of Note 5 to Section include the following : d (1) Nickel-iron alloys. These include materials used in submarine cables, induction coil cores, magnetic shielding, etc., because of their high magnetic permeability and low hysteresis. (2) Nickel-chromium or nickel-chromium-iron alloys. These include a variety of commercial materials featuring good strength and excellent resistance to oxidation at high temperature and scaling as well as to many corrosive environments. These materials are employed for the heater element in electrical resistance heating devices and are also used for components such as muffles and retorts used in the heat treatment of steels and other metals or in the form of pipe and tubin for hi temperature chemical or petrochemical . Also in this oup are speci alloys own as " super alloys " which have been develope specifically or hif~stren$h at the elevated temperatures prevailing in aircraft turbines where they are use for tur ine blades and vanes, combustion liners, transition sections, etc. Often these alloys contain molybdenum, tungsten, niobium, aluminium, titanium, etc., which are effective in significantly improving the strength of the nickel-base composition. prOcessinf s f2 ( 3 ) Nickel-copper alloys. These alloys, which in addition to corrosion resistance have good strength, are used in such applicat~onsas ropeller shafts and fasteners and are also used in pumps, valves, tubing and other forms o equipment exposed to certain mineral or organic acids or alkalis and salts. P This Chapter includes : (A) Nickel mattes, nickel oxide sinters and other intermediate products of nickel metallurgy and unwrought nickel, and nickel waste and scrap (headings 75.0 1 to 75.03). (B) Nickel powders and flakes (heading 75.04). (C) Products generally obtained b rollin for 'ng, drawing or extruding the unwrought nickel of heading 75.02 (headings 7z05 anf?5.0$. @) Tubes, pipes and fittings (heading 75.07), and electroplating anodes and other articles of heading 75.08, which covers all nickel articles, other than those covered .by Note 1 to Section XV or included in Chapter 82 or 83, or more specifically covered elsewhere in the Nomenclature. Products and articles of nickel may be subjected to various treatments to im rove the pro erties or appearance of the metal, etc. These treatments are generally those referre to at the encf'of the General Explanato Note to Chapter 72, and do not affect the classification of the goods. (See, however, the specia case of electroplating anodes (heading 75.08).) B The classification of composite artides is explained in the General Explanatory Note to Section XV.