Whereas (apart from a few exceptions such as machine saw blades) the preceding headings of this Chapter apply in the main to hand tools ready for use as they stand or after affixing handles, this heading covers an important group of tools which are unsuitable for use independently, but are designed to be fitted, as the case may be, into:
(A) hand tools, whether or not power-operated (e.g., breast drills, braces and die-stocks),
(B) machine-tools, of headings 84.57 to 84.65, or of heading 84.79 by reason of Note 7 to Chapter 84,
(C) tools of heading 84.67,
for pressing, stamping, punching, tapping, threading, drilling, boring, reaming, broaching, milling, gear-cutting, turning, cutting, morticing or drawing, etc., metals, metal carbides, wood, stone, ebonite, certain plastics or other materials, or for screwdriving.
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The tools of this heading may be either one-piece or composite articles.
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Composite tools consist of one or more working parts of base metal . . . attached to a base metal support either permanently, by welding or insetting, or as detachable parts. In the latter case, the tool consists of a base metal body and one or more working parts (blade, plate, point) locked to the body by a device comprising, for example, a bridge plate, a clamping screw or a spring cotter-pin with, where appropriate, a chip-breaking lip.
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The tools classified in this heading include:
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(9) Other interchangeable tools, such as:
(a) Tools for dressing, planning, grooving, lapping or trueing.
(b) Tools for morticing, moulding, or tonguing wood, including cutting chains for morticing wood.
(c) Tools for mixing, stirring, etc., materials such as paint, glue, mortar, mastic and coating slip.
(d) Screwdriver bits.