ISO INTERNATIONAL STANDARD 9180 First edition 1988-10-01 INTERNATIONAL ORGANIZATION FOR STANDARDIZATION ORGANISATION INTERNATIONALE DE NORMALISATION Black leads for wood-cased pencils - Classification and diameters Mines graphite pour crayons a papier - Classification et diametres Reference number ISO 9180: 1988 (E) rmitted without license from IHS Not for Resale ISO9180:1988 (E) Foreword Iso (the International Organization for Standardization) is a worldwide federation of national standards bodies (IsO member bodies). The work of preparing International Standards is normally carried out through IsoO technical committees. Each member body interested in a subject for which a technical committee has been established has the right to be represented on that committee. International organizations, govern- mental and non-governmental, in liaison with Iso, also take part in the work. IsO collaborates closely with the International Electrotechnical Commission (IEC) on all mattersofelectrotechnicalstandardization. Draft International Standards adopted by the technical committees are circulated to the member bodies for approval before their acceptance as International Standards by least 75 % approval by the member bodies voting. International Standard ISO 9180 was prepared by Technical Committee ISO/TC 10, Technical drawings. @ International Organization for Standardization, 1988 Printed in Switzerland Copyright IntemationalOrganizationforStandardization No reproduction or networking permited without license from IHs Not for Resale INTERNATIONAL STANDARD ISO 9180 :1988 (E) Black leads for wood-cased pencils - Classification and diameters Scope Classification This International Standard specifies a classification and Leads shall be classified according to their hardness degree into diameters for black leads used for wood-cased pencils. the following 17 types: 2 Definitions 9H, 8H, 7H, 6H, 5H, 4H, 3H, 2H, H, F, HB, B, 2B, 3B, 4B, 5B and 6B For the purposes of this International Standard, the following definitions apply. 2.1 black lead: Solid writing material which consists of 4 Diameters carbon (e.g. graphite) and a binding agent. The lead generates black lines which are erasable. Lead diameters shall be as specified in table 1. 2.2 hardness degree: Classification indicating increasing hard- ness from 6B to 9H and increasing line density from 9H to 6B. Table 1 - Diameters NOTE - A scientific definition of hardness degree is not yet avaitable. Hardness degree (see 2.2) Diameter mm 2.3 wood-cased pencil : Hand-held drawing tool which has 9H, 8H, 7H, 6H, 5H, 4H, 3H, 2H, H > 1,8 the lead permanently secured in a wood case and which is capable of withstanding the force involved in drawing. F, HB, B, 2B, 3B, 4B, 5B, 6B >2 No reproduction or networking permited without license from IHS Not for Resale