《BS-V-38-1967.pdf》由会员分享，可在线阅读，更多相关《BS-V-38-1967.pdf（8页珍藏版）》请在三一文库上搜索。
1、BRITISH STANDARD AEROSPACE SERIES CONFIRMED APRIL 1998 BS V 38:1967 Specification for Sitka spruce as rough timber UDC 629.13.01:674.032.475.576 Licensed Copy: London South Bank University, London South Bank University, Sat Dec 09 03:02:16 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS V 38:1967 This
2、 British Standard, having been approved by the Aerospace Industry Standards Committee and endorsed by the Chairman of the Engineering Divisional Council, was published under the authority of the General Council of the Institution on 29 December 1967 BSI 02-2000 The following BSI references relate to
3、 the work on this standard: Committee reference ACE/2 Draft for comment 66/23626 ISBN 0 580 34567 X Foreword This British Standard has been prepared, under the authority of the Aerospace Industry Standards Committee, at the request of the Timber Trade Federation of the United Kingdom to deal with th
4、e requirements for Sitka spruce as rough timber, previously specified in Ministry of Aviation Specification D.T.D. 28C which has recently been cancelled. Timber to this standard, rather than ungraded timber, should increase the probability of the material proving satisfactory for aerospace purposes.
5、 However, it should not be assumed that such timber will necessarily prove acceptable where there is a requirement to meet specifications for finished material. All dimensions and dimensional tolerances are given in both British and metric units. These two sets of requirements are not interchangeabl
6、e and the relevant set should be applied, depending on whether the timber is ordered in British or metric units. A British Standard does not purport to include all the necessary provisions of a contract. Users of British Standards are responsible for their correct application. Compliance with a Brit
7、ish Standard does not of itself confer immunity from legal obligations. Summary of pages This document comprises a front cover, an inside front cover, pages i and ii, pages 1 and 2, an inside back cover and a back cover. This standard has been updated (see copyright date) and may have had amendments
8、 incorporated. This will be indicated in the amendment table on the inside front cover. Amendments issued since publication Amd. No.DateComments Licensed Copy: London South Bank University, London South Bank University, Sat Dec 09 03:02:16 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS V 38:1967 BSI
9、02-2000i Contents Page ForewordInside front cover 1Scope1 2Quality1 3Seasoning1 4Characteristics1 5Freedom from defects1 6Dimensional tolerances2 7History2 8Identification2 Appendix A Method for the determination of moisture contentInside back cover Table 11 Table 22 Licensed Copy: London South Bank
10、 University, London South Bank University, Sat Dec 09 03:02:16 GMT+00:00 2006, Uncontrolled Copy, (c) BSI ii blank Licensed Copy: London South Bank University, London South Bank University, Sat Dec 09 03:02:16 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS V 38:1967 BSI 02-20001 1 Scope This British
11、Standard specifies the requirements, in both British and metric units, for two classes of Sitka spruce as rough timber for aerospace purposes. 2 Quality 2.1 The timber shall be of the best description obtainable of Sitka spruce (Picea sitchensis, Carr). 2.2 The timber shall have been cut from logs o
12、f a living tree. 3 Seasoning The timber shall have been either naturally or artificially seasoned, to the satisfaction of the inspector, to a moisture content, when determined by the method described in Appendix A, of not more than 27 % of the weight of the dry wood. 4 Characteristics 4.1 The rate o
13、f growth of any piece shall be not less than 18 nor more than 24 annual rings to each 3 in (metric: 75 mm) when measured in a radial direction through the zone of maximum growth on either end. 4.2 The material shall not contain bands of compression wood exceeding in aggregate 10 % of the width of th
14、e piece. 5 Freedom from defects 5.1 Rot and discoloration. All pieces shall be free from rot, dote and all forms of incipient decay and/or discoloration. 5.2 Tool marks and injury. All pieces shall be free from picaroon holes, hook marks, stripped edges or other damage that may be caused by bad hand
15、ling, to the satisfaction of the inspector. 5.3 Shakes. All pieces shall be free from shakes likely to seriously impair the value of the timber. 5.4 Pitch pockets 5.4.1 Pieces less than 10 ft (metric: 3.00 m) long and 6 in (metric: 150 mm) wide shall be free from pitch pockets. 5.4.2 Lengths of 10 f
16、t (metric: 3.00 m) and upwards may contain, on each of any two faces, one pitch seam or pocket not more than 2 in (metric: 50 mm) long or the equivalent in minor pockets provided that they are not in the same annual ring. Where the number of pitch pockets exceeds that amount, the disposition shall b
17、e such that an estimated yield of not less than 80 %, in lengths of not less than 10 ft (metric: 3.00 m) containing pitch pockets not exceeding the permissible limit, shall be obtained. 5.5 Sapwood and wane. Bright sapwood shall be allowed at the discretion of the inspector, having regard to the pos
18、sibility of subsequent decay or deterioration, and wane shall not exceed one half the estimated sapwood. The estimated yield of sound timber from lengths containing sapwood and/or wane shall be not less than 80 %, in clear lengths of not less than 10 ft (metric: 3.00 m). 5.6 Grain defects 5.6.1 Piec
19、es less than 10 ft (metric: 3.00 m) long shall be free from knots, burls, curls, gnarls, undulating and irregular grain, and any interruption in the growth which may constitute a weakness. 5.6.2 The slope of grain, when determined by visual inspection, shall not exceed the following: The class requi
20、red shall be stated in the contract or order. 5.6.3 Each piece 10 ft (metric: 3.00 m) or more long shall be free, on all four sides, from the defects referred to in 5.6.1 and shall comply with 5.6.2, to the extent that the estimated yield in clear lengths shall be in accordance with Table 1. Table 1
21、 1) Class 1: 1 in 15 2) Class 2: 1 in 12 BRITISH UNITS All dimensions are in feet METRIC UNITS All dimensions are in metres Length of piece Min. estimated yield Min. clear length Length of piece Min. estimated yield Min. clear length 10 up to and incl. 13 Over 13 % 90 80 8 10 3.00 up to and incl. 4.
22、00 Over 4.00 % 90 80 2.40 3.00 Licensed Copy: London South Bank University, London South Bank University, Sat Dec 09 03:02:16 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS V 38:1967 2 BSI 02-2000 5.7 Waste. Should the waste from all causes in any piece of timber exceed the allowance permitted in 5.4
23、.2, 5.5 and 5.6.3, the inspector may accept the timber provided that: 1) The contractor agrees to accept a measurement excluding the excess of this waste above 20 % or 10 %, as appropriate. 2) In no case is the total waste more than 33% % of the piece. 6 Dimensional tolerances 6.1 Tolerances on the
24、dimensions called for in the contract or order shall be allowed as follows: 1) Thickness. In accordance with Table 2, except that if full sawn material is called for in the contract or order it shall not be undersize at the time of manufacture but may be oversize within the appropriate tolerance giv
25、en in the table. 2) Width. In accordance with Table 2. 3) Length. To the nearest 6 in (metric: 150 mm). Table 2 7 History If required, the history of the parcel or consignment shall be declared by the contractor. 8 Identification Each piece passed by the inspector shall be stamped with the mark of t
26、he inspector and shall have the class and agreed chargeable dimensions marked on it. BRITISH UNITS All dimensions are in inches METRIC UNITS All dimensions are in millimetres Nominal width or thickness Tolerance Nominal width or thickness Tolerance 1 2 38 Over 8 plus 1/8 1/4 1/4 1/2 minus 1/32 1/16
27、1/8 1/4 27 50 75200 Over 200 plus 3 6.5 6.5 12.5 minus 1 1.5 3 6.5 Licensed Copy: London South Bank University, London South Bank University, Sat Dec 09 03:02:16 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS V 38:1967 BSI 02-2000 Appendix A Method for the determination of moisture content Take a sma
28、ll sample of the timber from an appropriate position, weigh it (W1) and then desiccate it in an oven at a temperature of 100105 C until the weight is constant (W0), taking great care to prevent any change in the moisture content between the cutting of the sample and the first weighing and also betwe
29、en removal from the oven and the subsequent weighing. Calculate the moisture content as follows: Moisture content, per cent = W1W0 W0 - -100 Licensed Copy: London South Bank University, London South Bank University, Sat Dec 09 03:02:16 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS V 38:1967 BSI 389
30、Chiswick High Road London W4 4AL BSI British Standards Institution BSI is the independent national body responsible for preparing British Standards. It presents the UK view on standards in Europe and at the international level. It is incorporated by Royal Charter. Revisions British Standards are upd
31、ated by amendment or revision. Users of British Standards should make sure that they possess the latest amendments or editions. It is the constant aim of BSI to improve the quality of our products and services. We would be grateful if anyone finding an inaccuracy or ambiguity while using this Britis
32、h Standard would inform the Secretary of the technical committee responsible, the identity of which can be found on the inside front cover. Tel: 020 8996 9000. Fax: 020 8996 7400. BSI offers members an individual updating service called PLUS which ensures that subscribers automatically receive the l
33、atest editions of standards. Buying standards Orders for all BSI, international and foreign standards publications should be addressed to Customer Services. Tel: 020 8996 9001. Fax: 020 8996 7001. In response to orders for international standards, it is BSI policy to supply the BSI implementation of
34、 those that have been published as British Standards, unless otherwise requested. Information on standards BSI provides a wide range of information on national, European and international standards through its Library and its Technical Help to Exporters Service. Various BSI electronic information se
35、rvices are also available which give details on all its products and services. Contact the Information Centre. Tel: 020 8996 7111. Fax: 020 8996 7048. Subscribing members of BSI are kept up to date with standards developments and receive substantial discounts on the purchase price of standards. For
36、details of these and other benefits contact Membership Administration. Tel: 020 8996 7002. Fax: 020 8996 7001. Copyright Copyright subsists in all BSI publications. BSI also holds the copyright, in the UK, of the publications of the international standardization bodies. Except as permitted under the
37、 Copyright, Designs and Patents Act 1988 no extract may be reproduced, stored in a retrieval system or transmitted in any form or by any means electronic, photocopying, recording or otherwise without prior written permission from BSI. This does not preclude the free use, in the course of implementin
38、g the standard, of necessary details such as symbols, and size, type or grade designations. If these details are to be used for any other purpose than implementation then the prior written permission of BSI must be obtained. If permission is granted, the terms may include royalty payments or a licensing agreement. Details and advice can be obtained from the Copyright Manager. Tel: 020 8996 7070. Licensed Copy: London South Bank University, London South Bank University, Sat Dec 09 03:02:16 GMT+00:00 2006, Uncontrolled Copy, (c) BSI