1、General purpose knuckle threads Part 3: Gauges for external and internal threads - Types, profiles and tolerances ICs 21.040.30 Descriptors: Screw threads, knuckle threads. Rundgewinde allgemeiner Anwendung -Teil 3: Lehren fr AuBen- und Innengewinde - Lehrenarten, Profile, Toleranzen In keeping with
2、 current practice in standards published by the International Organization for Standardization (ISO), a comma has been used throughout as the decimal marker. Foreword This standard has been prepared by the NormenausschuB Technische Grundlagen (Fundamentals in Tech- nology Standards Committee), Techn
3、ical Committee Prfung. It is based on the system of gauges for IS0 metric screw threads specified in IS0 1502) and the system of gauges for trapezoidal screw threads specified in DIN 103-9. Dimensions in mm 1 Scope and field of application This standard deals with gauges used for checking general pu
4、rpose knuckle threads with the thread profiles and nominal sizes specified in DIN 405-1 and subject to the tolerances specified in DIN 405-2. It specifies a gauging system in conformity with the Taylor principle for checking external and internal threads. It is recognized that other methods of check
5、ing may be used. Checking by means of the gauges specified in this standard is, however, always decisive. This gauging system is not suitable for checking threads in components made from thermosetting plastics. DIN 405-3 2 Normative references This standard incorporates, by dated or undated referenc
6、e, 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 incorporate
7、d in it by amendment or revision. For undated references, the latest edition of the publication referred to applies. DIN 103-9 IS0 metric trapezoidal screw threads -Gauging of external and internal threads - Gauge dimensions and design features DIN 405-1 General purpose knuckle threads - Profiles an
8、d nominal sizes DIN 405-2 General purpose knuckle threads - Tolerances DIN 2244 Screw threads - Terminology IS0 1502 : 1996 IS0 general-purpose metric screw threads - Gauges and gauging 3 Concepts For the purposes of this standard, the concepts specified in DIN 2244 shall apply. For symbols, see tab
9、le 1. l) See Explanatory notes. Continued on pages 2 to 14. Translation by DIN-Sprachendienst. In case of doubt, the German-language original should be consulted as the authoritative text I O No pari of this translation may be reproduced without the prior permission of Ref. No. DIN 405-3 : 1997-1 1
10、DIN Deutsches Institut fr Normung e. V., Berlin. Beutb Verlag GmbH, D-10772 Berlin, has the exclusive right of sale for German Standards (DIN-Normen). English price group 10 Sales No. O1 1 O 01.99 Page 2 DIN 405-3 : 1997-1 1 Symbol Quantity (or meaning) a, d I Pitch diameter of a workpiece external
11、thread I d2 Crest clearance Major diameter of a workpiece external thread I d3 I Minor diameter of a workpiece external thread I D2 D4 I Dl I Minor diameter of a workpiece internal thread Pitch diameter of a workpiece internal thread Major diameter of a workpiece internal thread El F, I Fundamental
12、deviation of a workpiece external thread (it is zero for tolerance position h) I I es Fundamental deviation of a workpiece internal thread (it is zero for tolerance position H) For thread profiles with truncated flanks, the radial distance between the pitch diameter line and the end of the straight
13、part of the flank in the direction of the crest m I pz Distance between the middle of the tolerance zone of a screw ring gauge, TR, and of a GO check plug gauge, Tcp For thread profiles with truncated flanks, the radial distance between the pitch diameter line and the end of the straight part of the
14、 flank in the direction of the root LML P I F3 I Height of profile with truncated flank of a plug gauge Least material limit Lead of single-start thread or pitch of multi-start thread I F4 I Height of profile with truncated flank of a ring gauge I R3 R-4 I h, = H, I Height of thread Root radius of p
15、rofile with complete flanks of a plug gauge Root radius of profile with truncated flanks of a plug gauge or ring gauge I Tolerance for plain plug gauges for checking diameter D, I Hl I H2 I Tolerance for plain ring or calliper gauges for major diameter of workpiece external threads I Tolerance on th
16、e size of GO check plugs for new plain calliper gauges and on wear check IHp I plugs for plain GO calliper gauges L I Symbol used to designate thread engagement group long N I Symbol used to designate thread engagement group normal MML I Maximum material limit Ph I Lead of multi-start thread Rl I Cr
17、est or root radius of profile with complete flanks of a plug gauge R2 I Crest radius of profile with complete flanks of a ring gauge R5 I Radius of gauges for gauging root diameter of external or internal thread Tolerance on the pitch diameter of GO and NOT GO screw check plugs, wear check plugs and
18、 setting plugs (continued) Page 3 DIN 405-3 1997-1 1 Td Ta Table 1 (concluded) Tolerance on the major diameter of a workpiece external thread Tolerance on the pitch diameter of a workpiece external thread I Symbol I Quantity (or meaning) TPh TPL Tolerance on the lead of a multiple-start gauge thread
19、 Tolerance on the pitch diameter of GO and NOT GO screw plug gauges I Td3 I Tolerance on the minor diameter of a workpiece external thread WGO WNG z, I TDI I Tolerance on the minor diameter of a workpiece internal thread Amount available for permissible wear of GO screw plug gauges and GO screw ring
20、 gauges Amount available for permissible wear of NOT GO screw plug gauges and NOT GO screw ring gauges Distance between middle of tolerance zone H, of a GO plug gauge and the lower limit of a workpiece minor diameter (equal to average wear limit for plain GO plug gauges) I TD2 I Tolerance on the pit
21、ch diameter of a workpiece internal thread Z, ZPL Tolerance on the lead of a single-start gauge thread or the pitch of a multiple-start gauge I Tp I thread Distance between middle of tolerance zone H, of a GO calliper gauge or ring gauge and the upper limit of a workpiece major diameter (equal to av
22、erage wear limit for plain ring and calliper gauges) Distance between middle of tolerance zone TpL of a GO screw plug gauge and the lower limit of a workpiece pitch diameter ZR I Tolerance on the pitch diameter of GO and NOT GO screw ring gauges I TR Distance between middle of tolerance zone TR of a
23、 GO screw ring gauge and the upper limit of a workpiece pitch diameter I Ta,/2 I Tolerance on the flank angle of a profile with complete flanks I T,/2 I Tolerance on the flank angle of a profile with truncated flanks 5 Types and use of gauges Gauges shall be selected based on the function and reliab
24、ility required of the threaded joint. In order to ensure the interchangeability of workpiece threads, at least gauge nos. 1 and 20 should be used. Gauge nos. 23, 13 and no. 15 are recommended to ensure that the actual thread sizes lie within the specified limits. 5.1 Gauges for workpiece external th
25、reads, and their check plugs and setting plugs Table 2: Gauges for workpiece external threads No. I Gauge type Solid GO screw ring gauge GO check plug for new solid GO screw ring gauges NOT GO check plug for new solid GO screw ring gauges Wear check plug for solid GO screw ring gauges Solid NOT GO s
26、crew ring gauge GO check plug for new solid NOT GO screw ring gauges NOT GO check plug for new solid NOT GO screw ring gauges Wear check plug for solid NOT GO screw ring gauges (continued) Page 4 DIN 405-3 1997-1 1 No. 20 21 22 23 24 Table 2 (concluded) Gauge type GO screw plug gauge NOT GO screw pl
27、ug gauge Plain GO screw plug gauge (for gauging minor diameter of internal threads) Plain NOT GO screw plug gauge (for gauging minor diameter of internal threads) GO screw plug gauge (for gauging major diameter of internal threads) No. Number of threads per 25,4 mm 10 8 6 4 9 10 11 12 13 14 15 16 17
28、 18 19 P RI R2 R3 2,54 0,606 0,65 0,561 3,175 0,757 0,813 0,702 4,233 1 ,o1 1,084 0,936 6,35 131 5 1,625 I ,404 Gauge type Plain GO ring gauge Plain GO calliper gauge GO check plug for new plain GO calliper gauges Wear check plug for plain GO calliper gauges Plain NOT GO calliper gauge GO check plug
29、 for new plain NOT GO calliper gauges Plain NOT GO screw ring gauge (only suitable for thin-walled components) GO screw calliper gauge (for gauging minor diameter of external threads) Plain setting plug for gauge no. 16 NOT GO screw calliper gauge (for gauging minor diameter of external threads) Pla
30、in setting plug for gauge no. 18 Gauging of the minor diameter of external threads (cf. DIN 405-2) is subject to agreement, since this is only required if clearance a, and the tolerance on the minor diameter are to be maintained. The ease of assembly of external threads in the area of the minor diam
31、eter (root clearance) is checked by a gauge no. 1. 5.2 Gauges for workpiece internal threads Gauging of the major diameter (minimum size) of internal threads by means of a gauge no. 24 shall be subject to agreement, since this is only required if clearance a, is to be maintained. Gauges for gauging
32、the major diameter (maximum size) of internal threads is not dealt with here, since no limit sizes have been specified for diameter D, in DIN 405-2. 6 Thread profiles for gauges 6.1 Profiles with complete flanks Plug gauges nos. 2, 6, 7, 8 and 20 shall have profiles with complete flanks as shown in
33、figure 1. The form of the clearance groove for gauge nos. 6, 7 and 8 is at the manufacturers discretion. However, the maximum size of the minor diameter must not be exceeded. Gauge no. 1 shall have a thread profile with complete flanks, as shown in figure 2. Radii R, to R3 shall comply with table 4.
34、 Table 4: Radii R, R, and R, The values given are nominal sizes, .e. deviations due to wear are permit- I ted. Page 5 DIN 405-3 : 1997-1 1 Number of threads per 25,4 mm 10 8 6 4 R5 max. 2,54 0,232 0,125 0,994 1,014 0,25 0,45 3,175 0,29 0,156 1,234 1,268 03 0,55 4,233 0,386 0,208 1,656 i ,689 0,4 0,7
35、5 6,35 0,579 0,312 2,484 2,535 0,6 1,1 R4 FI F* F3 F, max. f+T, or f-Tp Figure 1: Profile with complete flanks for gauges with external thread PtTp or f-p - Figure 3: Profile with truncated flanks for gauges with external thread Figure 2: Profile with complete flanks for gauges with internal thread
36、Figure 4: Profile with truncated flanks for gauges with internal thread Page 6 DIN 405-3 : 1997-1 1 Figure 5: Profile of GO calliper gauges for gauging minor diameter d, of workpiece Figure 6: Profile of GO plug gauges f8r gauging external diameter D, of workpiece external threads internal threads F
37、igure 7: Position of ridge which may be omitted Gauge no. 24 shall have a profile as shown in figure 6, with the radii R, and R, as given in table 5. Such a gauge shall be regularly checked for wear using indicating instruments. 7 Gauge length 7.1 Screw gauges The gauge lengths of screw gauges shall
38、 be as specified in table 6. The length of thread engagement on GO gauges should be at least 80 % of that of the workpiece thread for engagement group normal (N) or long (L) as specified in DIN 405-2. Lengths shorter than those specified in table 6 shall be the subject of agreement. The length of a
39、gauge extends only across the part of the thread that is completely formed. For this reason, any uncompletely formed threads shall be removed from the gauges. Table 6: Gauge lengths of screw gauges Gauge length I) I Gauge no. 0,8 x length of engagement3) 0,8 x length of engagement + P 3P 3P 3P 3P 7
40、8 16 3P 3P 3 P) 18 20 21 24 3P 3P 0,8 x length of engagement 3 P) I) Guideline dimensions. ) Since GO gauges are not used to check mated pairs, their length is limited 3, Length of thread engagement as in DIN 405-2. to 3 P. Page 7 DIN 405-3 : 1997-1 I 7.2 Plain gauges The gauge lengths of plain gaug
41、es shall be as specified in table 7. Gauge lengths shorter than those specified in table 7 shall be the subject of agreement. Table 7: Gauge lengths of plain gauges Gauge no. I I I Gauge length I) 0,8 x length of thread engagement) 3P 3P 3P 3P 3P 3P 4P 4P 0,8 x length of thread engagement2) 3P I) Gu
42、ideline dimensions. *) Length of thread engagement as in DIN 405-2. 8 Position of tolerance zones for gauges and calculation of gauge dimensions 8.1 Position of tolerance zones 8.1.1 Tolerance zones for pitch diameter of screw gauges The positions of tolerance zones for the pitch diameter of externa
43、l threads (ring gauges and check plugs) are shown in figure 8 and in figure 9 for internal threads of plug gauges. 8.1.2 Tolerance zones for plain gauges The positions of tolerance zones for plain gauges for the major or minor diameters of external threads (ring and calliper gauges) are shown in fig
44、ure 10 and in figure 11 for internal threads of plug gauges. 8.1.3 Tolerance zones for gauges for checking minor diameter of external threads and major diameter of internal threads Tolerance zones for gauges for checking diameter d, have not been specified and are not shown in figure 12. These gauge
45、 dimensions are embodied by the associated setting plugs, whose manufacturing tolerances are symmetrical to the nominal size. The position of the tolerance zone for gauges for checking diameter D, is shown in figure 12. 8.2 Calculation of gauge dimensions 8.2.1 Screw gauges for workpiece external th
46、reads The formulae for calculating the gauge dimensions for the major, pitch and minor diameters of screw gauges for checking the external threads (and their check plugs and setting plugs) are given in table 8. 8.2.2 Gauges for workpiece internal threads The formulae for calculating the gauge dimens
47、ions for the major, pitch and minor diameters of screw gauges for checking internal threads are given in table 9. Page 8 DIN 405-3 : 1997-1 1 zlw-L&;-$& I Workpiece MML (GO) A O 1? G I Wear check plug for new solid GO screw ring gauges I Wear limit for GO screw Workpiece MML (GO) ring gauge GO check
48、 plug for new solid GO screw ring gauges , c: Wear limit for NOT GO screw ring gauges Wear check plug for new solid - _ - - - - - - - -_ - -_ - NOT GO screw ring gauges Solid ring gauge I GO check plug for new solid NOT GO screw ring gauges Figure 8: Tolerance zones for pitch diameter of gauges and
49、their master gauges for checking workpiece external threads NOT GO screw plug gauge Workpiece LML (NOT GO) I u 1? _ _- - Wear limit for NOT GO plug gauge GO screw plug gauge I Wear limit for GO screw plug gauge - - - - - - - - - - -_ - - 1 - - - - - - - - - - - - - -_ - - _- -_ _ - - - Figure 9: Tolerance zones for pitch diameter of gauges and their check plugs for checking workpiece internal threads Page 9 DIN 405-3 1997-1 1 Is GO plug gauge z*!*& I s Wear limit for GO plug gauges G Wear limit for GO ring gauge or GO call
