1、July 2011 Translation by DIN-Sprachendienst.English price group 8No part of this translation may be reproduced without 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).ICS 79
2、.060.20!$sHA“1803730www.din.deDDIN EN 320Particleboards and fibreboards Determination of resistance to axial withdrawal of screwsEnglish translation of DIN EN 320:2011-07Spanplatten und Faserplatten Bestimmung des achsenparallelen SchraubenausziehwiderstandsEnglische bersetzung von DIN EN 320:2011-0
3、7Panneaux de particules et panneaux de fibres Dtermination de la rsistance larrachement des vis selon leur axeTraduction anglaise de DIN EN 320:2011-07SupersedesDIN EN 320:1993-08www.beuth.deDocument comprises pagesIn case of doubt, the German-language original shall be considered authoritative.1106
4、.11 DIN EN 320:2011-07 2 A comma is used as the decimal marker. National foreword This standard has been prepared by Technical Committee CEN/TC 112 “Wood-based panels” (Secretariat: DIN, Germany). The responsible German body involved in its preparation was the Normenausschuss Holzwirtschaft und Mbel
5、 (Timber and Furniture Standards Committee), Working Committee NA 042-02-15 AA Holzwerkstoffe Spiegelausschuss zu CEN/TC 112 und ISO/TC 89. Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. DIN and/or DKE shall not be held responsib
6、le for identifying any or all such patent rights. Amendments This standard differs from DIN EN 320:1993-08 as follows: a) the title of the standard has been modified; b) the scope has been extended to include particleboards; c) normative references have been updated. Previous editions DIN EN 320: 19
7、93-08 EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN 320 April 2011 ICS 79.060.20 Supersedes EN 320:1993English Version Particleboards and fibreboards - Determination of resistance to axial withdrawal of screws Panneaux de particules et panneaux de fibres - Dtermination de la rsistance larrach
8、ement des vis selon leur axe Spanplatten und Faserplatten - Bestimmung des achsenparallelen Schraubenausziehwiderstands This European Standard was approved by CEN on 17 March 2011. CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving thi
9、s European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN member. This European Standard exists in three official v
10、ersions (English, French, German). A version in any other language made by translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC Management Centre has the same status as the official versions. CEN members are the national standards bodies of Austr
11、ia, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom. EUROP
12、EAN COMMITTEE FOR STANDARDIZATION COMIT EUROPEN DE NORMALISATION EUROPISCHES KOMITEE FR NORMUNG Management Centre: Avenue Marnix 17, B-1000 Brussels 2011 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN 320:2011: EEN 320:2011 (E) 2
13、Contents Page Foreword 31 Scope 42 Normative references 43 Principles 44 Apparatus .45 Test pieces .55.1 Sampling .55.2 Dimensions .55.3 Conditioning .55.4 Preparation of test pieces .56 Procedure .66.1 Positioning of test pieces .66.2 Application of the force .76.3 Measurement of maximum load .77 E
14、xpression of results 87.1 For a test piece .87.2 For a board .88 Test report 8Bibliography 9DIN EN 320:2011-07 EN 320:2011 (E) 3 Foreword This document (EN 320:2011) has been prepared by Technical Committee CEN/TC 112 “Wood-based panels”, the secretariat of which is held by DIN. This European Standa
15、rd shall be given the status of a national standard, either by publication of an identical text or by endorsement, at the latest by October 2011, and conflicting national standards shall be withdrawn at the latest by October 2011. Attention is drawn to the possibility that some of the elements of th
16、is document may be the subject of patent rights. CEN and/or CENELEC shall not be held responsible for identifying any or all such patent rights. This document supersedes EN 320:1993. Compared to EN 320:1993, the following modifications have been made: a) Scope extended to include also particleboards
17、; b) Normative references updated. According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany
18、, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and the United Kingdom. DIN EN 320:2011-07 EN 320:2011 (E) 4 1 Scope This European Standard specifies a method for the dete
19、rmination of the resistance of fibreboards and particleboards to axial withdrawal of screws. 2 Normative references The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edit
20、ion of the referenced document (including any amendments) applies. EN 326-1, Wood-based panels Sampling, cutting and inspection Part 1: Sampling and cutting of test pieces and expression of test results EN ISO 1478, Tapping screws thread (ISO 1478:1999) 3 Principles Face and edge withdrawal of screw
21、s are determined by measuring the force required to withdraw a defined screw from the test piece. Edge withdrawal is only determined on boards of 15 mm thickness or more. 4 Apparatus 4.1 Testing machine, which shall be capable of applying in increasing axial load to the underside of the screw head t
22、hrough a suitable stirrup, whilst adequately restraining the test piece at the same time and measuring the maximum load to an accuracy of 1 %. 4.2 Metal jig. For testing face withdrawal of screws of boards of less than 15 mm thickness, the use of a metal jig with a central boring, which restrains th
23、e test piece (see Figure 1), is recommended. DIN EN 320:2011-07 EN 320:2011 (E) 5 Dimensions in millimetres Figure 1 Principle of testing face screwholding on boards of 15 mm thickness 5 Test pieces 5.1 Sampling Sampling and cutting of the test pieces shall be carried out according to EN 326-1. 5.2
24、Dimensions Five test pieces are taken from each sample board. The test pieces shall be square with a side length of (75 1) mm. 5.3 Conditioning The test pieces shall be conditioned to constant mass in an atmosphere with a mean relative humidity of (65 5) % and a temperature of (20 2) C. Constant mas
25、s is considered to be reached when the results of two successive weighing operations, carried out at an interval of 24 h, do not differ by more than 0,1 % of the mass of the test piece. NOTE The tests should be carried out not later than 1 h after removal of the test pieces from the conditioning env
26、ironment. 5.4 Preparation of test pieces After the test pieces have been conditioned, the screws shall be inserted into prebored pilot holes. Holes shall have a diameter of (2,7 0,1) mm and a depth of (19 1) mm. They shall be drilled perpendicular to the surface of the test piece, located at the mid
27、points of one face and two adjacent edges (on edges for boards of 15 mm thickness only. For this test, a steel screw, nominal size 4,2 mm 38 mm, with a thread no. ST 4,2 according to EN ISO 1478 and a thread pitch of 1,4 mm (see Figure 2) shall be used. The screws shall be inserted into the test pie
28、ces in such a way, that (15 0,5) mm of complete thread are embedded in the test piece. For testing face screwholding on test pieces of 15 mm, insert the screw in such a way that the length of the incomplete thread, y, protrudes on the opposite side of the test piece. DIN EN 320:2011-07 EN 320:2011 (
29、E) 6 Dimensions in millimetres Key y length of incomplete thread Figure 2 Parallel shank screw, nominal size 4,2 mm 38 mm, with a thread no. ST 4.2 according to EN ISO 1478, thread pitch: 1,4 mm 6 Procedure 6.1 Positioning of test pieces Mount the test pieces in the testing machine so that the surfa
30、ce under test is not supported at any point closer than 15 mm to the periphery of the embedded part of the screw, and is held perpendicular to the direction of the force applied to the screw (see Figure 3). For the testing of face screw withdrawal on boards of 15 mm thickness, the metal jig (see Fig
31、ure 1) shall be used in such a way that the screw is inserted into the boring in the centre of the metal jig, and the test piece is well restrained by the metal jig. DIN EN 320:2011-07 EN 320:2011 (E) 7 Dimensions in millimetres Key 1 Stirrup 2 Test piece t test piece thickness F load Figure 3 Screw
32、 withdrawal test on boards of 15 mm thickness (example) 6.2 Application of the force An increasing axial force is applied to the underside of the head of each screw in turn, through a stirrup incorporating a parallel-sided slot of suitable width to fit easily to the shank of the screw. Apply the axi
33、al load to the underside of the screw head at a constant rate of movement of (10 1) mm/min until maximum load is achieved. 6.3 Measurement of maximum load Record the maximum load, to the nearest 10 N, sustained by the test piece during the withdrawal test on the face and both edges (edge screw withd
34、rawal for boards 15 mm thickness only). DIN EN 320:2011-07 EN 320:2011 (E) 8 7 Expression of results 7.1 For a test piece Separate withdrawal strengths are recorded for the face and edges of the test piece, expressed to 10 N. The edge screwholding value of a test piece is the arithmetic mean of the
35、two results recorded on that test piece. The face screw withdrawal values of a test piece of less than 15 mm thickness shall be expressed in Newtons per millimetre (N/mm), by dividing the maximum load, in Newton, sustained by the test piece by its thickness, in millimetres, to 1 N/mm. 7.2 For a boar
36、d Face and edge screwholding values of a board are the arithmetic means of the results of all test pieced taken from that board, expressed to 10 N for boards of 15 mm thickness and to 1 N/mm for boards 15 mm thickness. 8 Test report According to EN 326-1. DIN EN 320:2011-07 EN 320:2011 (E) 9 Bibliography 1 EN 309, Particleboards Definition and classification 2 EN 316, Wood fibre boards Definition, classification and symbols DIN EN 320:2011-07
