{"id":260589,"date":"2024-10-19T17:15:34","date_gmt":"2024-10-19T17:15:34","guid":{"rendered":"https:\/\/pdfstandards.shop\/product\/uncategorized\/bs-3643-12007\/"},"modified":"2024-10-25T12:58:27","modified_gmt":"2024-10-25T12:58:27","slug":"bs-3643-12007","status":"publish","type":"product","link":"https:\/\/pdfstandards.shop\/product\/publishers\/bsi\/bs-3643-12007\/","title":{"rendered":"BS 3643-1:2007"},"content":{"rendered":"

This part of BS 3643 gives a compilation of principles and basic data for single-start, parallel screw threads having the ISO basic profile for triangular screw threads. Guidance on calculating limits of size for metric screw threads not included in Tables 1 to 14 is given in Annex B.<\/p>\n

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PDF Pages<\/th>\nPDF Title<\/th>\n<\/tr>\n
3<\/td>\nContents
1 Scope 1
2 Normative references 1
3 Terms and definitions and symbols 1
4 Basic profile 2
5 General plan 5
6 Basic dimensions 8
7 Tolerances – Principles and basic data 18
8 Tolerances – Deviations for constructional threads 35
9 Tolerances – Limits of sizes for hot-dip galvanized external screw threads to mate with internal screw threads tapped with tolerance position H or G after galvanizing 53
10 Tolerances – Limits of sizes for internal screw threads to mate with hot-dip galvanized external screw threads with maximum size of tolerance position h before galvanizing 55
Annexes
Annex A (informative) Notes for guidance 60
Annex B (informative) Examples of calculations of limits of size for metric screw threads 65
Bibliography 68
List of figures
Figure 1 – Basic profile of ISO metric thread 3
Figure 2 – Basic dimensions 8
Figure 3 – Tolerance positions with respect to zero line (basic size) 19
Figure 4 – Internal threads with tolerance position G 21
Figure 5 – Internal threads with tolerance position H 22
Figure 6 – External threads with tolerance positions e, f and g 22
Figure 7 – External threads with tolerance position h 23
Figure 8 – External root profile 31
Figure A.1 – Maximum material profiles for internal and external threads 61
Figure B.1 – Illustration of limits of size for external thread (see Example 1) 66
List of tables
Table 1 – Basic profile dimensions 4
Table 2 – Maximum nominal diameter 5
Table 3 – Diameter\/pitch combinations 6
Table 4 – Basic dimensions 9
Table 5 – Fundamental deviations for internal threads and external threads 24
Table 6 – Lengths of thread engagement 25
Table 7 – Minor diameter tolerances of internal threads (TD1) 26
Table 8 – Major diameter tolerances of external threads (Td) 27
Table 9 – Pitch diameter tolerances of internal threads (TD2) 28
Table 10 – Pitch diameter tolerances of external threads (Td2) 29
Table 11 – Minimum root radii 31
Table 12 – Recommended tolerance classes for internal threads 32
Table 13 – Recommended tolerance classes for external threads 32
Table 14 – Deviations 36
Table 15 – Deviations for hot-dip galvanized external threads 54 <\/td>\n<\/tr>\n
4<\/td>\nTable 16 – External thread limits for tolerance class 6az 55
Table 17 – Deviations for internal threads to mate with hot-dip galvanized external threads 57
Table 18 – Internal screw thread limits for tolerance class 6AZ 58
Table 19 – Internal screw thread limits for tolerance class 6AX 59
Table A.1 – Nominal stress areas for external screw threads – Coarse series 63
Table A.2 – Nominal stress areas for external screw threads – Fine series 64 <\/td>\n<\/tr>\n
5<\/td>\nForeword <\/td>\n<\/tr>\n
7<\/td>\n1 Scope
2 Normative references
3 Terms and definitions and symbols
3.1 Terms and definitions
3.1.1 basic profile <\/td>\n<\/tr>\n
8<\/td>\n3.2 Symbols
4 Basic profile
4.1 General
4.2 Dimensions <\/td>\n<\/tr>\n
9<\/td>\nFigure 1 Basic profile of ISO metric thread <\/td>\n<\/tr>\n
10<\/td>\nTable 1 Basic profile dimensions <\/td>\n<\/tr>\n
11<\/td>\n5 General plan
5.1 General
5.2 Designation
5.3 Choice of diameter and pitch
Table 2 Maximum nominal diameter <\/td>\n<\/tr>\n
12<\/td>\nTable 3 Diameter\/pitch combinations <\/td>\n<\/tr>\n
13<\/td>\nTable 3 Diameter\/pitch combinations (continued) <\/td>\n<\/tr>\n
14<\/td>\n6 Basic dimensions
6.1 General
6.2 Basic dimensions
Figure 2 Basic dimensions <\/td>\n<\/tr>\n
15<\/td>\nTable 4 Basic dimensions <\/td>\n<\/tr>\n
16<\/td>\nTable 4 Basic dimensions (continued) <\/td>\n<\/tr>\n
24<\/td>\n7 Tolerances – Principles and basic data
7.1 General
7.2 Structure of the tolerance system
a) A series of tolerance grades for each of the four screw thread diameters, as follows:
b) A series of tolerance positions:
c) A selection of recommended combinations of grades and positions (tolerance classes) giving the commonly used tolerance qualit… <\/td>\n<\/tr>\n
25<\/td>\nFigure 3 Tolerance positions with respect to zero line (basic size)
7.3 Designation <\/td>\n<\/tr>\n
27<\/td>\n7.4 Tolerance grades
7.5 Tolerance positions
Figure 4 Internal threads with tolerance position G <\/td>\n<\/tr>\n
28<\/td>\nFigure 5 Internal threads with tolerance position H
Figure 6 External threads with tolerance positions e, f and g <\/td>\n<\/tr>\n
29<\/td>\nFigure 7 External threads with tolerance position h <\/td>\n<\/tr>\n
30<\/td>\nTable 5 Fundamental deviations for internal threads and external threads <\/td>\n<\/tr>\n
31<\/td>\n7.6 Lengths of thread engagement
Table 6 Lengths of thread engagement <\/td>\n<\/tr>\n
32<\/td>\n7.7 Crest diameter tolerances
7.7.1 Minor diameter tolerances of internal threads (TD1)
Table 7 Minor diameter tolerances of internal threads (TD1) <\/td>\n<\/tr>\n
33<\/td>\n7.7.2 Major diameter tolerances of external threads (Td)
Table 8 Major diameter tolerances of external threads (Td)
7.8 Pitch diameter tolerances <\/td>\n<\/tr>\n
34<\/td>\nTable 9 Pitch diameter tolerances of internal threads (TD2) <\/td>\n<\/tr>\n
35<\/td>\nTable 10 Pitch diameter tolerances of external threads (Td2) <\/td>\n<\/tr>\n
36<\/td>\n7.9 Root contours <\/td>\n<\/tr>\n
37<\/td>\nFigure 8 External root profile
Table 11 Minimum root radii <\/td>\n<\/tr>\n
38<\/td>\n7.10 Recommended tolerance classes
Table 12 Recommended tolerance classes for internal threads
Table 13 Recommended tolerance classes for external threads <\/td>\n<\/tr>\n
39<\/td>\n7.11 Formulae
7.11.1 General
7.11.2 Fundamental deviations
7.11.3 Length of thread engagement <\/td>\n<\/tr>\n
40<\/td>\n7.11.4 Crest diameter tolerances
7.11.4.1 Tolerances for major diameter of external threads (Td), grade 6
7.11.4.2 Tolerances for minor diameter of internal threads (TD1), grade 6
a) Pitches 0.2 mm to 0.8 mm:
b) Pitch 1 mm and coarser:
7.11.5 Pitch diameter tolerances
7.11.5.1 Tolerances for pitch diameter of external threads (Td2) <\/td>\n<\/tr>\n
41<\/td>\n7.11.5.2 Tolerances for pitch diameter of internal thread (TD2)
8 Tolerances – Deviations for constructional threads
8.1 General
8.2 Deviations <\/td>\n<\/tr>\n
42<\/td>\nTable 14 Deviations <\/td>\n<\/tr>\n
43<\/td>\nTable 14 Deviations (continued) <\/td>\n<\/tr>\n
59<\/td>\n9 Tolerances – Limits of sizes for hot-dip galvanized external screw threads to mate with internal screw threads tapped with tolerance position H or G after galvanizing
9.1 General
9.2 Designation <\/td>\n<\/tr>\n
60<\/td>\n9.3 Deviations
Table 15 Deviations for hot-dip galvanized external threads
9.4 Limits of sizes – External screw threads – Coarse thread series <\/td>\n<\/tr>\n
61<\/td>\nTable 16 External thread limits for tolerance class 6az
10 Tolerances – Limits of sizes for internal screw threads to mate with hot-dip galvanized external screw threads with maximum size of tolerance position h before galvanizing
10.1 General <\/td>\n<\/tr>\n
62<\/td>\n10.2 Designation
10.3 Deviations <\/td>\n<\/tr>\n
63<\/td>\nTable 17 Deviations for internal threads to mate with hot-dip galvanized external threads <\/td>\n<\/tr>\n
64<\/td>\n10.4 Limits of sizes – Internal screw threads – Coarse thread series
Table 18 Internal screw thread limits for tolerance class 6AZ <\/td>\n<\/tr>\n
65<\/td>\nTable 19 Internal screw thread limits for tolerance class 6AX <\/td>\n<\/tr>\n
66<\/td>\nAnnex A (informative) Notes for guidance
A.1 Maximum material profile
A.2 Coatings
A.3 External threads – Stress areas
A.4 External threads – Minor diameters <\/td>\n<\/tr>\n
67<\/td>\nFigure A.1 Maximum material profiles for internal and external threads <\/td>\n<\/tr>\n
68<\/td>\nFigure A.1 Maximum material profiles for internal and external threads (continued) <\/td>\n<\/tr>\n
69<\/td>\nTable A.1 Nominal stress areas for external screw threads – Coarse series <\/td>\n<\/tr>\n
70<\/td>\nTable A.2 Nominal stress areas for external screw threads – Fine series <\/td>\n<\/tr>\n
71<\/td>\nAnnex B (informative) Examples of calculations of limits of size for metric screw threads <\/td>\n<\/tr>\n
72<\/td>\nFigure B.1 Illustration of limits of size for external thread (see Example 1) <\/td>\n<\/tr>\n
74<\/td>\nBibliography <\/td>\n<\/tr>\n<\/table>\n","protected":false},"excerpt":{"rendered":"

ISO metric screw threads – Principles and basic data<\/b><\/p>\n\n\n\n\n
Published By<\/td>\nPublication Date<\/td>\nNumber of Pages<\/td>\n<\/tr>\n
BSI<\/b><\/a><\/td>\n2009<\/td>\n76<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n","protected":false},"featured_media":260595,"template":"","meta":{"rank_math_lock_modified_date":false,"ep_exclude_from_search":false},"product_cat":[299,2641],"product_tag":[],"class_list":{"0":"post-260589","1":"product","2":"type-product","3":"status-publish","4":"has-post-thumbnail","6":"product_cat-21-040-10","7":"product_cat-bsi","9":"first","10":"instock","11":"sold-individually","12":"shipping-taxable","13":"purchasable","14":"product-type-simple"},"_links":{"self":[{"href":"https:\/\/pdfstandards.shop\/wp-json\/wp\/v2\/product\/260589","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/pdfstandards.shop\/wp-json\/wp\/v2\/product"}],"about":[{"href":"https:\/\/pdfstandards.shop\/wp-json\/wp\/v2\/types\/product"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/pdfstandards.shop\/wp-json\/wp\/v2\/media\/260595"}],"wp:attachment":[{"href":"https:\/\/pdfstandards.shop\/wp-json\/wp\/v2\/media?parent=260589"}],"wp:term":[{"taxonomy":"product_cat","embeddable":true,"href":"https:\/\/pdfstandards.shop\/wp-json\/wp\/v2\/product_cat?post=260589"},{"taxonomy":"product_tag","embeddable":true,"href":"https:\/\/pdfstandards.shop\/wp-json\/wp\/v2\/product_tag?post=260589"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}