Micrometers, callipers and gauges

90.17 - Drawing, marking-out or mathematical calculating instruments (for example, drafting machines, pantographs, p~otractors, drawing sets, slide rules, disc calculators); instruments for measuring length, for use in the band (for exam le, measuring rods and tapes, micrometers, callipers), not s p e a e d or inclu ed elsewhere in this Chapter. !i 9017.10 9017.20 90 17.30 9017.80 9017.90 - Drafting tables and machines, whether or not automatic - Other drawing, marking-out or mathematical calculating instruments - Micrometers, callipers and gauges - Other instruments - Parts and accessories This heading includes drawing, markin -out or mathematical calculating instruments. It also includes instruments for measuring lengt ,for use in the hand. g This heading does not, however, include : (a) Mitre boxes and tools used in the graphic arts (e.g., chisels, gouges, etching needles) (Chapter 82). (b) Graphic tablets and digitizers (heading 84.71). (c) Pattern generating apparatus designed to produce masks and reticles from photoresist coated substrates (such as optical, E-beam, focused ion beam, X-ray or laser beam apparatus) (heading 84.86). (d) Co-oxdinatographs of a type used for photogrammetrical purposes (heading 90.15). These include : (A) Drawing instruments. (1) Pantographs and eidographs for smaller, larger or same scale reproductions of maps, lans, drawings, parts to be machined, etc. The heading includes such instruments used ?or course plotting in navigation. (2) Drafting machines enerally using a system of parallelograms, with or without drawing boards or tab es. k The heading also covers drafting machines inco orating automatic data processing machines or working in conjunction with such mac ines. 'R (3) Drawing com asses, dividers, reduction compasses, s ring bows, mathematical drawing pew, &Bing wheels, etc., whether in a case (e-g., awlng sets) or separately. & (4) Set squares (standard, hatching, wood or metal working), adjustable squares, T squares (standard or articulated), drawing curves, rulers (flat, square, hatching (parallel rules), standard, etc.). (5) Protractors, fiom the ordinary protractors found in drawing sets to the complex protractors as used for example, in engineering. (6) Stencils of a kind clearly identifiable as bein specialised as drawing instruments. Stencils not so specialised are classified accor mg to their constituent material. d (B) Marking-out instruments. (Marking-out consists in marking construction lines, etc., on the surface of a part to be machined, sawn, etc.). (1) Beam compasses (marking, carpenters', etc.) with plain or divided laths. (2) Scribers and centre punches. (3) Surface plates used as a datum plane for marking-out or for checkin plane surfaces, etc. Strmght-edges and squares (of cast iron, stone, etc.) with a true p ane surface. K (4) V-blocks and X-blocks for supporting cylindrical workpieces. The headin does not cover engraving tools for working in the hand with self-contained motor (heading 8$.67). (C) Mathematical calculating instruments. Slide rules, disc calculators, cylindrical calculators and other calculating instruments based on the slide rule or other mathematical calculating princi le including, for instance, pocket-type adding and subtracting devices operated by the se ection of numbers with a stylus according to a given procedure. This group also includes rules and discs for calculating hotograph~cexposure times on adjustment by reference to the condition of the sky, time o day, aperture setting, type of subject and sensitivity of emulsion. P P Calculating or accounting machines, however, are excluded (heading 84.70). (D) Instruments for measuring length, for use in the hand. These instruments are capable of indicating the length, i.e., linear dimensions, of the olject to be measured, for exam le a line drawn or imaginary (straight or curved) on the object. The instruments are there ore capable of measuring dimensions such as diameters, de ths, thicknesses and heights which are indicated as a unit of length (e.g., millimetres). d e s e instruments must also have characteristics (size, weight, etc.) which enable them to be held in the hand to carry out the measurement. f Instruments specially designed to be used permanent1 mounted on a stand or other support or connected to machines or other apparatus by means o flexible tubing, cables, etc., to carry out the measurement are excluded (head~ng90.31). T This group includes : (1) Micrometers; instruments having a micrometric head , either of the screw- or screwless-type (the screwless-type inco orate a slide action and are usually electronic). They are used to measure, ;P or example, outside or inside diameters, thicknesses, screw thread pitch. The measurement may be read on the screw itself, on a dial or on a digital display. (2) Callipers (vernier, dial indicating or electronic), for measuring, e.g., diameters, depths, thicknesses. (3) Gauges, having an adjustable measuring device. Gauges without adjustable devices, used only for sizing parts or checking angles, forms, etc. (for example, plug gauges, ring gauges), are excluded (heading 90.31). (ez, (4) Comparators (dial e), used to check the inside or outside tolerance of dimensions reaming or rech cation checks). They incorporate a measurin rod, amplifying dl and transmission system (rack, gear, lever, spring, pneumatic, hy%raulic, etc.). 'Yg P (5) Measuring rods (plain or divided, strai t or folding and measurin tapes (e.g., spring rules, riband-rules, drum wound ands), inclu ing standard ro s, measuring sticks and the like. f The heading excludes measurin devices specially designed for surveying (land chains, levelling staves, ranging poles, ctc5 and winch-type measures for mine s h a h (heading 90.15). (6) Divided scales (school rulers, etc.), including V-shaped rules for measuring the diameter of convex bodies and vemcal measuring apparatus with movable crossheads. (7) Map measurers (opisometers); small instruments with or without a dial, used for measuring distances on maps, plans, etc. PARTS AND ACCESSORIES Sub'ect to the provisions of Notes 1 and 2 to this Cha ter (see the General Ex lanatory Note), the eading also covers arts and accessories identif?able as being suitable or use solely or principally with the macYlines, apparatus and instruments described above, e.f, micrometer extension anvils; stands for slip gauges; micrometer stands; hinges or joints for fo ding rules. h ? -