1、BRITISH STANDARD BS3821-2: 1974 Specification for Hardmetal dies and associated hardmetal tools Part2: As-sintered pellets and finished dies for drawing round wire UDC621.778.1.073:669.018.25+621.778.1.073:669426.2BS3821-2:1974 This British Standard, having been approved by the MechanicalEngineering
2、 IndustryStandards Committee,was published underthe authority of the Executive Board on 29July1974 BSI12-1999 First published November1964 First revision as Part2 July1974 The following BSI references relate to the work on this standard: Committee reference MEE/155 Draft for comment72/33677 DC ISBN
3、0 580 08132 X Co-operating organizations The Mechanical Engineering Industry Standards Committee, under whose supervision this British Standard was prepared, consists of representatives from the following Government departments and professional and industrial organizations: Associated Offices Techni
4、cal Committee Department of Trade and Industry, National Association of Consulting Engineers Engineering Laboratory Association of Hydraulic Equipment Electricity Supply Industry in England and Manufacturers Ltd. Wales Association of Mining Electrical and Engineering Equipment Users Association Mech
5、anical Engineers Federation of Manufacturers of Construction British Compressed Air Society Equipment and Cranes British Electrical and Allied Manufacturers Institution of Civil Engineers Association Institution of Gas Engineers British Gas Corporation Institution of Heating and Ventilating British
6、Gear Manufacturers Association Engineers British Internal Combustion Engine Institution of Mechanical Engineers* Manufacturers Association Institution of Plant Engineers British Mechanical Engineering Institution of Production Engineers Confederation London Transport Executive British Pump Manufactu
7、rers Association Machine Tool Trades Association British Steel Industry* Ministry of Defence Crown Agents for Oversea Governments and Ministry of Defence, Army Department Administrations National Coal Board Department of Employment (HM Factory Process Plant Association Inspectorate) Railway Industry
8、 Association of Great Britain Department of the Environment Royal Institute of British Architects Department of Trade and Industry, Energy Telecommunication Engineering and Technology Manufacturing Association Department of Trade and Industry (Marine) The organizations marked with an asterisk in the
9、 above list, together with the following, were directly represented on the committee entrusted with the preparation of this British Standard: British Non-ferrous Metals Federations Institute of Iron and Steel Wire High Conductivity Copper Group Manufacturers British Hard Metal Association Individual
10、 experts British Independent Steel Producers Association Amendments issued since publication Amd. No. Date of issue CommentsBS3821-2:1974 BSI 12-1999 i Contents Page Co-operating organizations Inside front cover Foreword ii 1 General 1 1.1 Scope 1 1.2 Definitions 1 1.3 Symbols 1 2 Pellet 2 2.1 Hardm
11、etal grades 2 2.2 Forms, dimensions and tolerances 2 3 Case 5 3.1 Material 5 3.2 Forms and dimensions 6 4 Finished die 7 4.1 General requirement 7 4.2 Assembly 7 4.3 Accuracy 7 4.4 Marking 7 Appendix A Information to be given when purchasing hardmetal as-sintered pellets and hardmetal dies 8 Figure
12、1 Symbols for as-sintered pellets for drawing round wire 2 Figure 2 Symbols for finished dies for drawing round wire 2 Figure 3 Types of pellet 3 Figure 4 Pellet and assembled dies 6 Table 1 Dimensions of as-sintered pellets 4 Table 2 Tolerance on diameter of pellet, d 02 5 Table 3 Tolerance on heig
13、ht of pellet, h 02 5 Table 4 Tolerance on diameter of bearing of pellet, d 01 5 Table 5 Dimensions of pellets and cases 6 Table 6 Tolerance on diameter of bearing of finished die 7 Table 7 Maximum tolerable departure from roundness ofdiameterofbearing 7 Publications referred to Inside back coverBS38
14、21-2:1974 ii BSI 12-1999 Foreword First published as BS3821:1964 this Part of this British Standard has been revised to include dimensions of as-sintered pellets, and other Parts added to extend the range of the standard. Prepared under the authority of the Mechanical Engineering Industry Standards
15、Committee, full cognizance has been taken of ISO Recommendation R524 “Hard metal wire drawing dies. Interchangeability dimensions of pellets and cases”. Account has also been taken of ISO work which relates to dimensions of as-sintered pellets and note taken of ISO/R1684 “Wire, bar and tube drawing
16、dies Designation Marking Dimension”, which is an extension of ISO/R524. The manufacture of hardmetal wire drawing dies involves highly specialized techniques and development. For this reason, every care has been taken to establish a British Standard containing requirements calculated to ensure the f
17、irst rate quality and performance of the finished dies, which will not impede the research and development of new techniques in a healthy and progressive industry. The standard does not lay down the requirements for hardmetal grades. This information is applicable to all types of hardmetal dies and
18、associated hardmetal tools, and therefore a separate standard, BS4276 “Hard metal for wire, bar and tube drawing dies”, has been published relating exclusively to grading and quality of hardmetal for dies, including wire drawing dies. Part1 of this British Standard specifies designation and marking
19、of as-sintered pellets and finished dies, and Part3 of the standard specifies as-sintered pellets and finished dies for drawing round bar. The standard has been produced with the fullest co-operation of die users and manufacturers, and the manufacturers of wire drawing machinery. A British Standard
20、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 British Standard does not of itself confer immunity from legal obligations. Summary of pages This document comprises a front cover, an i
21、nside front cover, pagesi andii, pages1 to8, an inside back cover and a back cover. This standard has been updated (see copyright date) and may have had amendments incorporated. This will be indicated in the amendment table on the inside front cover.BS3821-2:1974 BSI 12-1999 1 1 General 1.1 Scope Th
22、is Part of this British Standard specifies the dimensions of as-sintered pellets and finished hardmetal dies and certain quality aspects of finished dies for drawing ferrous and non-ferrous round wire. The dies are intended to produce wire up to12mm diameter from steel and13mm diameter from non-ferr
23、ous material. NOTEThe titles of the British Standards referred to in this standard are listed on the inside back cover. 1.2 Definitions For the purposes of this British Standard, the following definitions apply: 1.2.1 hardmetal sintered material characterized by high strengthand wear resistance, wit
24、h hard substances,e.g.carbides of refractory metal, as the main component and with a metallic binder phase 1.2.2 pellet that component of a wire drawing die which is made from hardmetal. Prior to finishing it is usually termed the “as-sintered pellet” or “rough pellet” 1.2.3 case that component of a
25、 wire drawing die into which the pellet is positively fixed 1.2.4 bore the bore of the pellet including the entry, drawing, bearing and exit portions 1.2.5 finished die the assembly of the case and the pellet after all operations have been completed 1.2.6 nominal size the nominal size of the die; eq
26、ual to the nominal size of the wire which it will produce 1.2.7 measured size the actual measured value of the bearing diameter 1.2.8 designating size the size of the die expressed as pellet diameter (d 2 ) case diameter (d 3 ) (see Table 5) 1.3 Symbols For the purposes of this British Standard the
27、symbols shown in Figure 1 and Figure 2 relate to the dimensions of as-sintered pellets and finished dies, respectively, for drawing round wire.BS3821-2:1974 2 BSI 12-1999 2 Pellet 2.1 Hardmetal grades Pellets for wire drawing dies shall be manufactured from grades of hardmetal selected from BS4276.
28、2.2 Forms, dimensions and tolerances The as-sintered pellet shall conform to the dimensions given in Table 1, according to type as shown in Figure 3. Tolerances on the dimensions of as-sintered pellets shall be in accordance with Table 2, Table 3 and Table 4. Figure 1 Symbols for as-sintered pellets
29、 for drawing round wire Figure 2 Symbols for finished dies for drawing round wireBS3821-2:1974 BSI 12-1999 3 Figure 3 Types of pelletBS3821-2:1974 4 BSI 12-1999 Table 1 Dimensions of as-sintered pellets Type d 02 h 02 2 0 1 2 0 2 2 0 4 d 01 d 04 d 05 I II II mm 8 8 8 mm 4 4 4 degrees 10 10 degrees 9
30、0 90 90 degrees 90 90 90 mm 0.1 0.3 mm 4.2 3.6 3.6 mm 2.2 2.2 2.2 I II II II II II 10 10 10 10 10 10 8 8 8 8 8 8 10 10 12 12 12 90 90 90 90 90 90 90 90 90 90 90 90 0.1 0.3 0.6 1.0 1.5 7.6 5.5 6.0 6.0 6.0 6.0 6.2 3.5 3.5 4.0 4.0 4.5 II II II II II 12 12 12 12 12 10 10 10 10 10 10 12 12 12 12 90 90 90
31、 90 90 90 90 90 90 90 0.2 0.6 1.0 1.4 1.8 7.0 7.0 7.0 7.0 8.0 4.5 4.5 5.0 5.0 5.0 II II II II II II 14 14 14 14 14 14 12 12 12 12 12 12 10 12 12 12 12 14 60 60 60 60 60 60 75 75 75 75 75 75 0.2 0.6 1.0 1.4 1.8 2.4 7.0 7.0 7.0 7.0 8.0 8.0 5.0 5.0 5.0 5.0 5.5 6.0 II II II II II II II II 16 16 16 16 16
32、 16 16 16 13 13 13 13 13 13 13 13 10 12 12 12 12 14 14 14 60 60 60 60 60 60 60 60 75 75 75 75 75 75 75 75 0.3 0.6 1.0 1.4 1.8 2.2 2.6 3.0 8.0 8.0 8.5 9.0 9.0 9.5 9.5 9.5 5.0 5.0 5.0 5.5 6.0 6.5 6.5 7.0 II II II II II III III 20 20 20 20 20 20 20 17 17 17 17 17 17 17 12 12 14 14 14 16 16 60 60 60 60
33、60 60 60 60 60 60 60 60 60 60 1.0 1.6 2.2 2.8 3.4 4.0 4.6 8.5 8.5 10.0 10.0 11.0 12.0 12.5 6.0 6.5 6.5 7.0 8.0 8.5 9.0 II II II III III III III 25 25 25 25 25 25 25 20 20 20 20 20 20 20 12 14 14 16 16 16 16 60 60 60 60 60 60 60 60 60 60 60 60 60 60 2.0 2.7 3.4 4.1 4.8 5.5 6.5 11.5 12.0 13.0 13.5 14.
34、0 14.5 15.5 7.0 7.5 8.0 8.5 9.0 10.0 11.0 II II III III III III III 30 30 30 30 30 30 30 24 24 24 24 24 24 24 14 14 16 16 16 16 16 60 60 60 60 60 60 60 60 60 60 60 60 60 60 3.0 3.7 4.5 5.5 6.5 8.0 9.5 15.0 16.0 17.0 18.0 18.0 19.0 20.0 9.0 9.0 10.0 10.0 12.0 13.5 16.0BS3821-2:1974 BSI 12-1999 5 Tabl
35、e 2 Tolerance on diameter of pellet,d 02Table 3 Tolerance on height of pellet, h 02Table 4 Tolerance on diameter of bearing ofpellet, d 01 3 Case 3.1 Material The case shall be manufactured from material selected in accordance with the following: 1) Up to28mm external diameter; from steelcomplying w
36、ith the requirements of BS970-1,070M20 1) , or from steels equivalent or superior in mechanical properties, or from brass complying with the requirements of BS249. 2) Over28mm external diameter; from steelcomplying with the requirements of BS970-1,070M20 1)or from steels equivalent or superior in me
37、chanical properties. d 02 Tolerance From Up to and including mm 8 mm 16 mm +0.6 +0.2 20 30 +0.7 +0.2 h 02 Tolerance From Up to and including mm 4 mm 10 mm 0.2 12 17 0.3 20 24 0.4 d 01 Tolerance From Up to and including mm mm 0.3 mm +0 0.075 0.3 0.5 +0 0.10 0.5 2.0 +0 0.15 2.0 4.0 +0 0.20 4.0 6.0 +0
38、0.25 6.0 10.0 +0 0.30 1) Steel070M20 was previously designated En3A in the superseded En series.BS3821-2:1974 6 BSI 12-1999 3.2 Forms and dimensions The case shall conform to the dimensions given in Table 5, according to form as shown in Figure 4. The case may be of straight (code letter Z) or taper
39、ed (code letter K) form. When a tapered form is required, an included angle of2=6 shall be provided, in which event d 3is the diameter of the larger and of the taper (see Figure 4). Table 5 Dimensions of pellets and cases Figure 4 Pellet and assembled dies Pellet Case Designation size Steel (referen
40、ce letter A) Non-ferrous (reference letter B) d 2 h 2 d 1 s a d 1 s a l 4 2 2 d 3 h 3 l s l 6 b min. max. min. min. max. min. max. 0.25 0.13 mm mm mm mm mm mm mm mm mm mm deg. deg. mm mm mm mm 8/28 8 4 0.1 1 3.5 0.1 1.5 3.25 1 90 90 28 12 3 5 10/28 10 8 0.2 2 4 0.2 2.5 3.75 2 16 12/28 12 10 0.3 3 4.
41、5 0.3 3.5 4.25 2.5 20 7 14/28 14 12 0.4 4 5 0.4 4.5 4.75 3 60 75 28 c 22 3 7 14/43 43 16/43 16 13 0.5 5 5.5 0.5 6 5 3.5 43 25 4 8 20/43 20 17 1.5 6.5 6.75 1.5 8 6 4.5 60 60 43 32 10 25/53 25 20 2.5 9 8 2.5 10.5 7.25 5 53 35 5 25/75 75 c 30/75 30 24 3.5 12 9 3.5 13 8.5 6 75 40 6 NOTE 1d 1minis the mi
42、nimum and preferred diameter of bearing at the first application. NOTE 2d 1maxis the maximum diameter of bearing which is recommended for drawing steel wire having a tensile strength up to900MPa in the drawn condition and for drawing wires of non-ferrous metal having a tensile strength up to600MPa i
43、n the drawn condition. NOTE 3The diameter of bearing d 1required by the user should be chosen within the limits d 1maxand d 1min . The tolerance of bearing should be specified by the user. a s minb For information only c The value28 instead of43 is generally suitable for drawing wires of lower tensi
44、le strength, e.g.copper. The value75 instead of53 is generally suitable for drawing wires of higher tensile strength, e.g.steel. d 2 d 1max 2 - =BS3821-2:1974 BSI 12-1999 7 4 Finished die 4.1 General requirement The finished die, consisting of hardmetal pellet and case, shall comply with the require
45、ments specified in4.2 and4.3. 4.2 Assembly The pellet shall be positively and permanently fixed in its correct position in the case. The method of fixing shall be such as to ensure adequate support to the peripheral face and the base of the pellet. 4.3 Accuracy 4.3.1 Diameter of bearing. The diamete
46、r of bearing shall be accurate within the appropriate tolerance as given in Table 6. Table 6 Tolerance on diameter of bearingoffinished die 4.3.2 Roundness of bearing. When assessed inaccordance with BS3730, departures from idealroundness shall not exceed the values given inTable 7. Bearing diameter
47、s too small to be evaluated by direct instrumental means shall be assessed by checking the roundness or the wire drawn through the die. Table 7 Maximum tolerable departure fromroundness of diameter of bearing 4.3.3 Finish. All surfaces of the pellet bore shall be free from scratch marks and surface
48、irregularities other than those naturally inherent in the finishing process. When assessed in accordance with BS1134 the roughness value shall be not greater than0.14m R a . Bores too small to permit direct instrumental evaluation shall be assessed using plastics replica techniques similar to those
49、outlined in BS1134. Bores too small to permit evaluation by plastics replica techniques (of the order of0.762mm and smaller) shall be assessed by examination for detrimental surface irregularities only, using a watchmakers eyeglass of 10 magnification. 4.3.4 Concentricity. The external diameter of case and pellet shall be concentric with the bearing diameter within0.25mm total indicator reading. 4.3.5 Squareness of faces. The front and back fa
