This part of BS 1580 specifies limits of sizes, and tolerances, for single-start, clearance-fit unified screw threads, in inch units with diameters below in.<\/p>\n
This part of BS 1580 specifies unified screw threads from Number 0 (0.060 in diameter) to Number 12 (0.216 in diameter), known as the \u201cnumbered sizes\u201d in the following standard series:<\/p>\n
a coarse thread (UNC) series;<\/p>\n<\/li>\n
a fine thread (UNF) series;<\/p>\n<\/li>\n
for Number 12 threads, an extra fine (UNEF) 32 threads per inch diameter\/pitch combination.<\/p>\n
\nNOTE Unified screw threads below in diameter for attachment purposes and for general use in the aircraft industry are specified in Annex A.<\/p>\n<\/blockquote>\n<\/li>\n<\/ul>\n
PDF Catalog<\/h4>\n
\n
\n PDF Pages<\/th>\n PDF Title<\/th>\n<\/tr>\n \n 3<\/td>\n Contents
1 Scope 1
2 Normative references 1
3 Terms and definitions and symbols 1
4 Thread profiles 1
5 Diameter\/pitch combinations 2
6 Tolerance classes 2
7 Tolerances, allowances and limits of size for uncoated threads 2
8 Coated threads 3
9 Designation of threads 4
10 Gauges 4
Annexes
Annex A (normative) Unified screw threads below in diameter for attachment purposes and for general use in the aircraft industry 16
Bibliography 17
List of tables
Table 1 – Unified screw threads below in diameter, standard series 5
Table 2 – Unified screw threads below in diameter, standard series – Limits of size 6
Table 3 – Coarse thread series (UNC) below in diameter – Limits and tolerances for finished uncoated threads – External threads Class 2A 8
Table 4 – Coarse thread series (UNC) below in diameter – Limits and tolerances for finished uncoated threads – Internal threads Class 2B 8
Table 5 – Coarse thread series (UNC) below in diameter – Limits and tolerances for finished uncoated threads – External threads Class 3A 9
Table 6 – Coarse thread series (UNC) below in diameter – Limits and tolerances for finished uncoated threads – Internal threads Class 3B 9
Table 7 – Fine thread series (UNF) below in diameter – Limits and tolerances for finished uncoated threads – External threads Class 2A 10
Table 8 – Fine thread series (UNF) below in diameter – Limits and tolerances for finished uncoated threads – Internal threads Class 2B 10
Table 9 – Fine thread series (UNF) below in diameter – Limits and tolerances for finished uncoated threads – External threads Class 3A 11
Table 10 – Fine thread series (UNF) below in diameter – Limits and tolerances for finished uncoated threads – Internal threads Class 3B 11
Table 11 – Extra fine thread series (UNEF) below in diameter – Limits and tolerances for finished uncoated threads – External threads Classes 2A and 3A 12
Table 12 – Extra fine thread series (UNEF) below in diameter – Limits and tolerances for finished uncoated threads – Internal threads Classes 2B and 3B 12
Table 13 – Coarse thread series (UNC) sizes below in diameter – Basic dimensions 13 <\/td>\n<\/tr>\n\n 4<\/td>\n Table 14 – Fine thread series (UNF) sizes below in diameter – Basic dimensions 13
Table 15 – Extra fine thread series (UNEF) sizes below in diameter – Basic dimensions 14
Table 16 – Thread data for unified thread form 24 t.p.i. to 80 t.p.i. 15 <\/td>\n<\/tr>\n\n 5<\/td>\n Foreword <\/td>\n<\/tr>\n \n 7<\/td>\n 1 Scope
2 Normative references
3 Terms and definitions and symbols
3.1 Terms and definitions
3.2 Symbols
4 Thread profiles <\/td>\n<\/tr>\n\n 8<\/td>\n 5 Diameter\/pitch combinations
6 Tolerance classes
a) external threads:
b) internal threads:
7 Tolerances, allowances and limits of size for uncoated threads <\/td>\n<\/tr>\n\n 9<\/td>\n 8 Coated threads
8.1 General
8.2 Class 2A external threads
8.3 Class 2AG external threads
8.4 Class 3A external threads
8.5 Class 2B internal threads <\/td>\n<\/tr>\n\n 10<\/td>\n 8.6 Class 3B internal threads
9 Designation of threads
9.1 Basic designation
a) the thread number;
b) the number of threads per inch;
c) the thread series, UNC, UNF or UNEF;
d) the thread class, 2A, 2AG, 3A, 2B or 3B.
9.2 Additional designations
10 Gauges <\/td>\n<\/tr>\n\n 11<\/td>\n Table 1 Unified screw threads below in diameter, standard series (Extension of Table 1 of BS 1580-1) <\/td>\n<\/tr>\n \n 12<\/td>\n Table 2 Unified screw threads below in diameter, standard series – Limits of size (Extension of Table 2 of BS 1580-1) <\/td>\n<\/tr>\n \n 14<\/td>\n Table 3 Coarse thread series (UNC) below in diameter – Limits and tolerances for finished uncoated threads – External threads Class 2A (Extension of Table 5 of BS 1580-1)
Table 4 Coarse thread series (UNC) below in diameter – Limits and tolerances for finished uncoated threads – Internal threads Class 2B (Extension of Table 6 of BS 1580-1) <\/td>\n<\/tr>\n\n 15<\/td>\n Table 5 Coarse thread series (UNC) below in diameter – Limits and tolerances for finished uncoated threads – External threads Class 3A (Extension of Table 7 of BS 1580-1)
Table 6 Coarse thread series (UNC) below in diameter – Limits and tolerances for finished uncoated threads – Internal threads Class 3B (Extension of Table 8 of BS 1580-1) <\/td>\n<\/tr>\n\n 16<\/td>\n Table 7 Fine thread series (UNF) below in diameter – Limits and tolerances for finished uncoated threads – External threads Class 2A (Extension of Table 11 of BS 1580-1)
Table 8 Fine thread series (UNF) below in diameter – Limits and tolerances for finished uncoated threads – Internal threads Class 2B (Extension of Table 12 of BS 1580-1) <\/td>\n<\/tr>\n\n 17<\/td>\n Table 9 Fine thread series (UNF) below in diameter – Limits and tolerances for finished uncoated threads – External threads Class 3A (Extension of Table 13 of BS 1580-1)
Table 10 Fine thread series (UNF) below in diameter – Limits and tolerances for finished uncoated threads – Internal threads Class 3B (Extension of Table 14 of BS 1580-1) <\/td>\n<\/tr>\n\n 18<\/td>\n Table 11 Extra fine thread series (UNEF) below in diameter – Limits and tolerances for finished uncoated threads – External threads Classes 2A and 3A
Table 12 Extra fine thread series (UNEF) below in diameter – Limits and tolerances for finished uncoated threads – Internal threads Classes 2B and 3B <\/td>\n<\/tr>\n\n 19<\/td>\n Table 13 Coarse thread series (UNC) sizes below in diameter – Basic dimensions (Extension of Table 15 of BS 1580-1)
Table 14 Fine thread series (UNF) sizes below in diameter – Basic dimensions (Extension of Table 16 of BS 1580-1) <\/td>\n<\/tr>\n\n 20<\/td>\n Table 15 Extra fine thread series (UNEF) sizes below in diameter – Basic dimensions (Extension of Table 17 of BS 1580-1) <\/td>\n<\/tr>\n \n 21<\/td>\n Table 16 Thread data for unified thread form 24 t.p.i. to 80 t.p.i. (Extension of Table 26 of BS 1580-1 with identical values in the overlapping range of 40 t.p.i. to 24 t.p.i.) <\/td>\n<\/tr>\n \n 22<\/td>\n Annex A (normative) Unified screw threads below in diameter for attachment purposes and for general use in the aircraft industry
A.1 Tolerance class
A.2 Allowance for uncoated threads
A.3 Limits of size
A.4 Coated threads
A.5 Designation of threads
A.6 Gauges <\/td>\n<\/tr>\n\n 23<\/td>\n Bibliography <\/td>\n<\/tr>\n<\/table>\n","protected":false},"excerpt":{"rendered":" Unified screw threads – Screw threads with diameters below \u00bc in. Requirements<\/b><\/p>\n
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\n Published By<\/td>\n Publication Date<\/td>\n Number of Pages<\/td>\n<\/tr>\n \n BSI<\/b><\/a><\/td>\n 2007<\/td>\n 24<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n","protected":false},"featured_media":260406,"template":"","meta":{"rank_math_lock_modified_date":false,"ep_exclude_from_search":false},"product_cat":[300,2641],"product_tag":[],"class_list":{"0":"post-260403","1":"product","2":"type-product","3":"status-publish","4":"has-post-thumbnail","6":"product_cat-21-040-20","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\/260403","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\/260406"}],"wp:attachment":[{"href":"https:\/\/pdfstandards.shop\/wp-json\/wp\/v2\/media?parent=260403"}],"wp:term":[{"taxonomy":"product_cat","embeddable":true,"href":"https:\/\/pdfstandards.shop\/wp-json\/wp\/v2\/product_cat?post=260403"},{"taxonomy":"product_tag","embeddable":true,"href":"https:\/\/pdfstandards.shop\/wp-json\/wp\/v2\/product_tag?post=260403"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}