DIN_267-30[1].en

ICS 21.060.10M echanische Verbindungselemente –Technische Lieferbedingungen –Teil 30: M etrische gewinde-furchende Schrauben der Festigkeitsklasse 10.9In keeping with current practice in standards published by the International Organization for Standardization (ISO), a comma has been used throughout as the decimal marker.ForewordThis standard has been prepared by Technical Committee K einschrauben of the Normenausschuss Mechanische Verbindungselemente (Fasteners Standards Committee). It includes additional specifications for case hardened and tempered metric thread rolling screws as in DIN EN ISO 7085.Ref.No.DIN 267-30:2001-02English price group 05Sales No.010509.01DEUTSCHE NORM February 2001267-30{Continued on pages 2 and 3.©No part of this translation may be reproduced without the prior permission ofDIN Deutsches Institut für Normung e.V., Berlin. Beuth Verlag GmbH , 10772Berlin, Germany,has the exclusive right of sale for German Standards (DIN-Normen).Technical delivery conditions for fastenersPart 30: Metric thread rolling screws of property class 10.9Translation by DIN-Sprachendienst.In case of doubt, the German-language original should be consulted as the authoritative text.All dimensions are in millimetres.1ScopeThis standard specifies requirements for metric thread rolling screws of property class 10.9 designed to produce internal threads with nominal diameters from 2mm to 10mm in materials with a maximum Vickers hardness of 130HV or a maximum Brinell hardness of 124HB, which fit general purpose ISO metric screw threads for use in general applications.2Normative referencesThis standard incorporates, by dated or undated reference, provisions from other publications. These normative 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 standard only when incorporated in it by amendment or revision. For undated references, the latest edition of the publication referred to applies.DIN 4000-2Tabular layouts of article characteristics for bolts, screws and fit bolts DIN EN 20898-7Mechanical properties of fasteners –Part 7: Torsional test and minimum torques forbolts and screws with nominal diameters 1mm to 10mm (ISO 898-7:1992)DIN EN ISO 898-1Mechanical properties of fasteners made of carbon steel and alloy steel –Part 1: Bolts,screws and studs (ISO 898-1:1999)DIN EN ISO 4042Fasteners –Electroplated coatings (ISO 4042:1999)DIN EN ISO 10683Fasteners –Non-electrically applied zinc flake coatings (ISO/DIS 10683:1999)*)DIN EN ISO 15330Fasteners –Preloading test for the detection of hydrogen embrittlement –Parallelbearing surface method (ISO 15330:1999)DIN ISO 261ISO general purpose metric screw threads –General plan (ISO 261:1998)*)Currently at draft stage.Page2DIN267-30:2001-023MaterialsThread rolling screws shall be made of carbon steel or alloy steel as specified in DIN EN ISO898-1.4Mechanical requirementsThread rolling screws shall meet the requirements for property class 10.9 as specified in DIN EN ISO898-1 and DIN EN20898-7. The head geometry of such screws shall ensure compliance with the requirements for property class 10.9 as specified in DIN EN ISO898-1, in particular with regard to minimum ultimate tensile strength. See table 1 for minimum breaking torques and tensile breaking loads.Table 1:Mechanical and performance requirementsNominal thread Minimum breaking Maximum drive Minimum tensilediameter, in mm torque, in Nm torque1), in Nm breaking load, in N 20,450,2321502,51,00,5353031,90,9552303,53,01,5705044,42,2913059,34,7148006168,02090084020,038100108140,5603001)Equal to half the minimum breaking torque.4.1Heat treatmentFinished screws shall be quenched and tempered as specified in DIN EN ISO898-1 for property class 10.9 in order to meet the mechanical and performance requirements listed in table 1 of this standard.4.2Breaking torqueWhen tested as specified in subclause 5.1, the minimum breaking torque shall be as given in table 1. Failure shall not occur at the head/shank intersection or in the clamped section of the screw.4.3Ability to form a mating threadThe screw shall, without permanent deformation of its own thread when viewed at X10 magnification, form a mating thread in a test plate in accordance with subclause 5.2.2. During the driveability test, the drive torque shall not exceed the values specified in table 1.The thread formed by the screw in the test plate shall be capable of accommodating a fastener threaded in accordance with DIN ISO261, tolerance class 6h.Form and arrangement of the screw section used for thread rolling shall be at the manufacturer’s discretion. The length of this section shall not exceed 4 P (cf. figure 1).Figure 1:Length of thread rolling section4.4Surface finishThe surface finish shall be in accordance with DIN EN ISO4042 or DIN EN ISO10683.For thread rolling screws of property class 10.9 there is a risk of failure due to hydrogen embrittlement, especially if they are electroplated. Therefore, a test shall be carried out to detect hydrogen embrittlement (e.g. the ‘Parallel bearing surface method’ specified in DIN EN ISO15330). If embrittlement is discovered, modification of the manufacturing process will be necessary.Page3DIN267-30:2001-02 Where screws are to be electroplated, hydrogen embrittlement relief treatment in accordance withDIN EN ISO4042 is recommended.NOTE:Non-electrolytically applied coatings should be given preference.5TestingThread rolling screws shall be tested using the methods specified in DIN EN ISO898-1.5.1Torsional testThe screw to be tested shall be securely clamped in a suitable device (cf. DIN EN20898-7), with at least two full threads projecting above the device and at least two full threads held in the clamping device.Using a suitable calibrated torque-measuring device, torque shall be applied to the screw until failure occurs. The torque required to cause failure shall be recorded as the breaking torque.5.2Driveability test5.2.1Determining the thread rolling capabilityThe screw to be tested shall be driven into a test plate (cf. subclause 5.2.2) until at least one full thread projects above the surface of the plate.The thread rolling process shall be started by applying an axial force of 50N for nominal thread diameters up to 5mm and 100N for nominal thread diameters over 5mm. In arbitration cases, the driving speed shall not exceed 30min–1 (30r.p.m). The maximum torque measured during the test shall be regarded as the drive torque. Where necessary, a lubricant may be used to achieve the required drive torque.5.2.2Test plateThe test plate shall be made of aluminium alloy steel having a hardness of 75HB to 105HB and shall have a thickness equal to twice the nominal screw diameter. The hole diameter shall be as given in table 2.Table 2:Test plate thickness and hole diameterNominal thread diameter22,533,5456810 Plate thickness4567810121620Hole diameter Min.1,802,252,753,153,654,505,407,309,20 Max.1,832,282,783,183,684,535,437,349,246Torque wrenchesTorque wrenches used in torsional and driveability tests shall be accurate to within t3% of the specified torques. Alternatively, a torque sensing power device of the same accuracy may be used. In arbitration cases, a manually operated torque wrench shall be used.7MarkingThread rolling screws shall be marked as specified in DIN EN ISO898-1.8DesignationThe designation of thread rolling screws conforming to this standard shall include the symbol ‘GF’ to identify the screw type.EXAMPLE:Designation of an M10 thread rolling screw (GF) with a nominal length, l, of 60mm, of property class10.9, provided with a type A2C electroplated coating as in DIN EN ISO4042:Screw DIN267–M10GFé60–10.9–A2CThe DIN4000-2-1.11 tabular layout of article characteristics shall apply to screws covered in this standard.Other relevant standardsDIN7500-2Thread rolling screws for ISO metric thread–Guideline values for hole diametersDIN EN ISO7085Mechanical and performance requirements of case hardened and tempered metric thread rolling screws (ISO7085:1999)。