1、BRITISH STANDARD BS 4372:1968 Specification for Engineers steel measuring rulesBS4372:1968 This British Standard, having been approved by the MechanicalEngineering IndustryStandards Committee,was published underthe authority of the Executive Board on 30December1968 BSI 08-1999 The following BSI refe
2、rences relate to the work on this standard: Committee reference MEE/59 Draft for comment 67/18560 ISBN 580 00371 X Co-operating organizations The Mechanical Engineering Industry Standards Committee, under whose supervision this British Standard was prepared, consists of representatives from the foll
3、owing Government departments and scientific and industrial organizations: Associated Offices Technical Committee Association of Consulting Engineers Association of Mining Electrical and Mechanical Engineers Board of Trade British Chemical Plant Manufacturers Association British Compressed Air Societ
4、y British Electrical and Allied Manufacturers Association British Gear Manufacturers Association British Internal Combustion Engine Manufacturers Association British Mechanical Engineering Federation British Pump Manufacturers Association British Steel Industry Crown Agents for Oversea Governments a
5、nd Administrations Electricity Council, the Central Electricity Generating Board and the Area Boards in England andWales Engineering Equipment Users Association Gas Council Institute of Marine Engineers Institution of Civil Engineers Institution of Gas Engineers Institution of Heating and Ventilatin
6、g Engineers Institution of Mechanical Engineers Institution of Mechanical Engineers (Automobile Division) Institution of Production Engineers Locomotive and Allied Manufacturers Association of Great Britain London Transport Board Machine Tool Trades Association Ministry of Defence, Army Department M
7、inistry of Labour (H.M. Factory Inspectorate) Ministry of Power Ministry of Technology Ministry of Public Building and Works Ministry of Technology National Engineering Laboratory Ministry of Transport National Coal Board National Physical Laboratory (Ministry of Technology) Radio Industry Council R
8、oyal Institute of British Architects Amendments issued since publication Amd. No. Date CommentsBS4372:1968 BSI 08-1999 i Contents Page Co-operating organizations Insidefrontcover Foreword ii 1 General 1 1.1 Scope 1 1.2 Definitions 1 1.3 Marking 1 2 Steel rules 1 2.1 Material and finish 1 2.2 Recomme
9、nded lengths 2 2.3 Suggested sections 2 2.4 Graduation lines and figuring 2 2.5 Accuracy 2 3 Folding steel rules 3 3.1 Construction 3 3.2 Material and finish 3 3.3 Suggested sections 3 3.4 Graduation lines and figuring 4 3.5 Accuracy 4 Figure 1 to Figure 5 Typical examples of rules complying with th
10、e standard 5 Figure 6 to Figure 9 Examples of simplified scales suggested for the future 7 Table 1 Suggested sections for steel rules 2 Table 2 Accuracy of graduation 3 Table 3 Suggested sections for folding steel rules 3BS4372:1968 ii BSI 08-1999 Foreword This standard makes reference to the follow
11、ing British Standards: BS 427, Method for Vickers hardness test Part 1. Testing of metals. BS 970, Wrought steels in the form of bars, billets and forgings, up to6 in ruling section, for automobile and general engineering purposes. En series. BS 1134, Centre-line-average height method for the assess
12、ment of surface texture. BS 1224, Electroplated coatings of nickel and chromium. This British Standard has been prepared to meet the demand for a specification for steel rules in metric units for use in engineering. In recognition of the fact that the metre and the millimetre are recommended SI unit
13、s, it is officially recommended that the figuring on the rules covered by this standard be in millimetres wherever possible. However, in those cases where practical considerations make it preferable to use centimetre figuring this is permissible as a second choice. Typical rules complying with the s
14、tandard are illustrated. Recommendations for preferred lengths are included and are based on the known demands of countries already using the metric system. A British Standard does not purport to include all the necessary provisions of a contract. Users of British Standards are responsible for their
15、 correct application. Compliance with a British 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 to 7 and a back cover. This standard has been updated (see copyright date) and ma
16、y have had amendments incorporated. This will be indicated in the amendment table on theinside front cover.BS4372:1968 BSI 08-1999 1 1 General 1.1 Scope This British Standard specifies requirements for steel rules of up to1 metre nominal length, for use in engineering. The standard comprises three s
17、ections as follows: Section 1: General; Section 2: Steel rules; Section 3: Folding steel rules. NOTEInch/metric rules are not included in this standard but it is recognized that they will continue in use for some time to come; the general requirements for these rules and for the metric graduation on
18、 them are in accordance with the provisions of this standard and the inch graduation should be of comparable accuracy. 1.2 Definitions For the purposes of this British Standard, the following definitions apply: steel rule a graduated continuous length of steel with one or two square datum ends foldi
19、ng steel rule two or more graduated lengths of steel connected together by swivel joints, with two square datum ends 1.3 Marking The rule shall be marked with at least the manufacturers name or trade mark and the number of this British Standard, i.e.BS4372. NOTEThe mark BS4372 on or in relation to t
20、he product is a claim by the manufacturer that it complies with the requirements of the standard. The British Standards Institution is the owner of a registered certification trade mark. This is shown below, enclosed in the words “Approved to British Standard”. This mark can be used only by the manu
21、facturers licensed under the certification mark scheme operated by the BSI. The presence of this mark on or in relation to a product is an assurance that the goods have been produced to comply with the requirements of the British Standard under a system of supervision, control and testing operated d
22、uring manufacture and including periodical inspection at the manufacturers works in accordance with the certification mark scheme of the BSI. Further particulars of the terms of licence may be obtained from the Director, British Standards Institution,2 Park Street, London,W.1. 2 Steel rules 2.1 Mate
23、rial and finish 2.1.1 Steel rules shall be manufactured in one continuous length from carbon steel, carbon steel matt chrome plated in accordance with BS1224 1)or rust-resisting steel. The steel shall be hardened and tempered and shall have a hardness of450 to550HV 2) . 1) BS1224, “Electroplated coa
24、tings of nickel and chromium”. 2) BS427, “Method for Vickers hardness test”, Part1, “Testing of metals”.BS4372:1968 2 BSI 08-1999 2.1.2 Suitable rust-resisting steels are En56C and En56D to BS970 3) . The faces and edges of the rules shall have a clean but not highly reflective finish. The surface r
25、oughness of unplated rules shall not exceed0.8 micrometre CLA (32micro inch CLA), assessed in accordance with BS1134 4) . 2.2 Recommended lengths It is recommended that the lengths given below be regarded as preferred and that those in the first choice series be selected wherever possible: 2.3 Sugge
26、sted sections Rules are at present made in various widths and thicknesses; the sections given inTable 1 are suggested for future guidance. Rules should not be so thick that parallax impairs the accuracy of reading. Table 1 Suggested sections for steel rules 2.4 Graduation lines and figuring 2.4.1 Gr
27、aduation lines. Graduation lines shall be of uniform width, square to the edges. They shall extend from the rule edge for a distance of at least1.5mm and shall differ in length so as to clearly indicate the subdivisions of the basic measurement unit. The width of these lines shall not be less than0.
28、1mm nor more than0.2mm and shall not exceed half the width of the scale interval. 2.4.2 Figuring. Figuring, which may refer to either one or both scales on a rule face, shall indicate: 1) the distance in millimetres of each10mm graduation line, or 2) the distance in centimetres of each1cm graduation
29、 line from a square end of the rule. When rules are “graduated” in cm, then the first figured graduation line should be marked “cm”. NOTERecommended SI units are the metre and the millimetre and it is officially recommended that preference be given to figuring in millimetres wherever possible. The d
30、egree of scale interval shall be marked within25mm of the commencement of, and be aligned with, such scale intervals. 2.4.3 Marking of graduation lines and figuring. Graduation lines and figuring shall be effected by metal removal; this shall have a minimum depth of0.02mm for carbon steel and0.01mm
31、for rust-resisting steel rules. The graduation lines and figuring of rules shall provide a durable contrast to the surface. 2.5 Accuracy When referred to the standard reference temperature of20 C, the tolerances in2.5.1 to2.5.4 shall apply. 2.5.1 Rule edges shall be straight to within0.1mm on any le
32、ngth up to300mm. 2.5.2 Rule edges shall be parallel to within0.1mm on any length up to300mm. 2.5.3 Flat ends shall be square to the rule edges to within0.05mm over the width of the rule. 3) BS970, “Wrought steels. En series”. 4) BS1134, “Centre-line-average height method for the assessment of surfac
33、e texture”. First choice: 150 300 500 1 000 mm Second choice: 100 200 600 mm Nominal rule length Material section Narrow Standard mm mm 100 mm 150 mm 200 mm 13 0.4 20 0.75 300 mm 13 0.4 28 1.0 500 mm 600 mm 1 m 20 0.5 a 30 1.5 a This section is not normally available in the1m length.BS4372:1968 BSI
34、08-1999 3 2.5.4 Graduation lines shall be accurate to within the tolerances specified inTable 2. These tolerances apply to the distances between the centre lines of the graduation lines. Table 2 Accuracy of graduation 3 Folding steel rules 3.1 Construction 3.1.1 The rule shall consist of “legs” of a
35、pproximately equal length, connected end to end by permanent joints to form a straight line. Both extreme ends of the rule shall be flat and square to the rule edges. 3.1.2 The joints shall locate the legs in a straight line during service and also allow the rule to fold into a convenient length. Bo
36、th ends of the rule may be fitted with tips if so desired; such tips shall be within the graduated length. The tip shall be of the same width as the rule and shall fit flush with the rule end and edges. Tips shall be securely fastened to the outer face only of the appropriate legs. 3.2 Material and
37、finish 3.2.1 Legs. Each leg shall be manufactured in one continuous length from carbon steel, carbon steel matt chrome plated in accordance with BS1224 5)or rust-resisting steel. The steel shall be hardened and tempered and shall have a hardness of450 to550HV. Suitable rust-resisting steels are En56
38、C and En56D to BS970 6) . 3.2.2 Joint components. The exposed components of rust-resisting rules shall also be of rust-resisting material. 3.3 Suggested sections The sections given in the table below are suggested for future guidance. Rules should not be so thick that parallax impairs the accuracy o
39、f reading. Table 3 Suggested sections for folding steel rules Rule length Departure from nominal Up to and inc. 300 mm Over 300 mm up to and inc. 500 mm Over 500 mm up to and inc. 1 m mm mm mm Distance between any two graduation lines on a single scale 0.1 0.2 0.25 Distance between any two adjacent
40、graduation lines 0.05 0.05 0.05 Position of the 10 mm graduation line from its flat end datum 0.08 0.08 0.08 5) BS1224, “Electroplated coatings of nickel and chromium”. 6) BS970, “Wrought steels. En series”. Nominal length of leg Material section mm Up to 250 mm 13 0.5 Over 250 mm 20 0.75BS4372:1968
41、 4 BSI 08-1999 3.4 Graduation lines and figuring 3.4.1 Graduation lines. Graduation lines shall be of uniform width, square to the edges. They shall extend from the rule edge for a distance of at least1.5mm for rules of less than15mm width, marked on both edges; graduation lines on all other rules s
42、hall have a length of not less than2.5mm. Graduation lines shall differ in length so as to clearly indicate the subdivisions of the basic measurement unit. The width of these lines shall not be less than0.12mm nor more than0.25mm and shall not exceed half the width of the scale interval. 3.4.2 Figur
43、ing. Figuring shall indicate: 1) the distance in millimetres of each10mm graduation line, or 2) the distance in centimetres of each1cm graduation line from the end of the rule. When rules are “graduated” in cm, then the first figured graduation line should be marked “cm”. NOTERecommended SI units ar
44、e the metre and the millimetre and it is officially recommended that preference be given to figuring in millimetres wherever possible. Those figures whose legibility or location would be adversely affected by the joints may be omitted. Where the size of a joint component obscures the identity of som
45、e graduation lines, the joint component shall be marked to indicate the major graduation, e.g.300mm. The degree of scale interval shall be marked within25mm of the commencement of, and be aligned with, such interval. 3.4.3 Marking of graduation lines and figuring. Graduation lines and figuring shall
46、 be effected by metal removal; this shall have a minimum depth of0.02mm for carbon steel and0.01mm for rust-resisting steel rules. The graduation lines and figuring of rules shall provide a durable contrast to the surface. 3.5 Accuracy When referred to the standard reference temperature of20 C, the
47、tolerances in3.5.1 to3.5.4 shall apply. 3.5.1 Flat ends shall be square with the rule edges to within0.05mm over the width of the rule. 3.5.2 Each joint shall ensure the alignment of the graduated edges of its two associated legs to within0.25mm. It shall also locate the positional continuity of the
48、 graduation to within0.2mm. 3.5.3 Each individual leg of the rule shall be accurately graduated with a maximum permissible error between the centre lines of any two graduation lines on a single scale in accordance with the tolerances given inTable 2. 3.5.4 The positional error of the centre line of
49、the first and last10mm or1cm graduation lines relative to its nearest square end shall not exceed0.12mm.BS 4372:1968 BSI 08-1999 5 Typical examples of rules complying with the standard (See Foreword) Figure 1 Figure 2 Figure 3 BS 4372:1968 6 BSI 08-1999 Figure 4 Figure 5 BS4372:1968 BSI 08-1999 7 Example of simplified scales suggested for the future Figure 6 Figure 7 Figure 8 Figure 9 BS 4372:1968 BSI 389 Chiswick High Road London W4 4AL BSIBritishStandardsInstitution BSI is the independent national body responsible
