1、 No part of this translation may be reproduced without the prior permission ofDIN Deutsches Institut fr Normung e. V., Berlin. Beuth Verlag GmbH, 10772 Berlin, Germany,has the exclusive right of sale for German Standards (DIN-Normen).Ref. No. DIN 874-2:2003-11English price group 05 Sales No. 010508.
2、05Document comprises 3 pages.ICS 17.040.30Geometrische Produktspezikation (GPS) Lineale Teil 2: Haarlineale Mae, Technische LieferbedingungenIn keeping with current practice in standards published by the International Organization for Standardization (ISO), a comma has been used throughout as the de
3、cimal marker.874-2StraightedgesPart 2: Knife-edge straightedges Dimensions and technical delivery conditionsTranslation by DIN-Sprachendienst.In case of doubt, the German-language original should be consulted as the authoritative text.ForewordThis standard has been prepared by Technical Committee Ei
4、ndimensionale Lngenprftechnik of the Nor-menausschuss Technische Grundlagen (Fundamentals in Technology Standards Committee).AmendmentsThis standard differs from the August 1973 edition as follows:a) reference is made to DIN EN ISO 14253-1 regarding proof of conformance with this standard;b) the sta
5、ndard has been editorially revised and brought up-to-date to reect current technology.Previous editionsDIN 874: 1931-10; DIN 874-2: 1973-08.1 ScopeThis standard species dimensions and tolerances for knife-edge straightedges up to 1 000 mm in length.2 Normative referencesThis standard incorporates, b
6、y dated or undated reference, provisions from other publications. These nor-mative references are cited at the appropriate places in the text, and the titles of the publications are listed below. For dated references, subsequent amendments to or revisions of any of these publications apply to this s
7、tandard only when incorporated in it by amendment or revision. For undated references, the latest edition of the publication referred to applies.DIN EN ISO 1 Geometrical product specications (GPS) Standard reference temperature for geo-metrical product specications and verication (ISO 1:2002)DIN EN
8、ISO 14253-1 Geometrical product specications (GPS) Inspection by measurement of work-pieces and measuring equipment Part 1: Decision rules for proving conformance or non-conformance with specications (ISO 14253-1:1998)ISO 1101:2004 Geometrical Product Specications (GPS) Geometrical tolerancing Toler
9、ances of form, orientation, location and run-out3 ConceptsFor the purposes of this standard, the concepts dened in ISO 1101 apply.DEUTSCHE NORM November 2003Supersedes August 1973 edition.Page 2DIN 874-2:2003-114 Dimensions and designation4.1 DimensionsDimensions of straightedges shall be as in tabl
10、e 1.The design shown in gure 1 is for illustrative purposes only; however, the dimensions of knife-edge straight-edges shall be as specied here.Key1 Grip plate, with non-slip surface2 Plane of symmetry3 Knife edge, lappedFigure 1: Knife-edge straightedgeTable 1: Dimensions (values in mm)l h b 2 Min.
11、 Min.7510020 515020025 530040030 8500 40 10750 50 121 000 60 124.2 DesignationDesignation of a knife-edge straightedge of 200 mm length:Knife-edge straightedge DIN 874 2005 Requirements5.1 Reference temperatureThe reference temperature shall be 20 C as in DIN EN ISO 1.5.2 Straightness toleranceThe s
12、traightness tolerance, t, for the knife edge shall be determined using the following equation:t = 2 m + 4 106lRounding the result obtained using the equation given above gives the tolerances listed in table 2. Section XPage 3DIN 874-2:2003-11Table 2: Straightness tolerancesl mmt a m75100150223200300
13、4003345007501 0004561) Values apply with the straightedge at an an-gle of at least 15 to the normal of the refer-ence plane.5.3 MaterialKnife-edge straightedges shall be of hardened steel or another similar material, such as ceramics. Grips shall be of a thermally insulating material. All materials
14、shall be either selected by the manufacturer alone or in agreement with the customer.5.4 FinishThe side faces of the knife edge shall be lapped and have an anti-glare surface.5.5 HardnessThe Vickers hardness of steel knife-edge straightedges, measured at the knife edge, shall be at least 575 HV 5.6
15、Verication6.1 StraightnessDeviations from straightness shall be determined using suitable material measures. The straightness of the knife edge may also be veried visually by placing the edge on a reference surface and checking it against backlighting.6.2 Proof of conformanceProof of conformance with this standard shall be provided in accordance with DIN EN ISO 14253-1.
