Bsi bs 2a 231 1993 (1999) iso 3353 1992

BRITISH STANDARD BS 2A 231 1993 ISO 3353 1992 Rolled threads for bolts — Lead and runout requirements UDC 621 882 2 629 7 http //dx doi org/10 3403/00307258U BS 2A 231 1993 This British Standard, havi[.]

ISO 3353:1992

U C 6 1.8 2.2:6 9.7

This British Stan ard,ha ing

b en pre ared u der the direction

of the Aerosp ce Stan ards Polcy

Commite , was publshed u der

the authority of the Stan ards

Bo rd an comes into efect on

1 July 1 9

© BSI 0 -1 9

The folowing BSI references

relate to the work on this

stan ard:

Commite reference ACE/12

Draft for comment 9 /75 7 DC

ISBN 0 5 0 2 8 6 7

The prep ration of this British Stand rd was entrusted b the Aerosp ce

Stand rds Polcy Commit e ( ACE/-) to Tech ical Commit e ACE/ 12, upon

which the folowing bodies were represented:

The Association of Electronic , Telecommu ications and Busines Equipment

Industries

British Industrial Fastener Federation

Ministry of Defence

Society of British Aerosp ce Comp nies Ltd

Am endm ents is ued sinc publ cation

Pag e

National foreword

This British Stand rd has be n prep red u der the direction of the Aerosp ce

Stand rds Polcy Commit e It is identical with ISO3 5 :19 2Aer ospa ce —

R ol led thr ea d s f r bolts — Lea d a nd r unout r equir ements publshed b the

International Org anization for Stand rdization ( ISO) It super edes

BS A231:19 2 which is withdrawn

A British Stand rd do s not purport to include al the neces ary prov isions of a

contract User of British Stand rds are responsible for their cor ect a pl cation

Com pl anc with a British Standard do s not of itselfc nfer im munity

f om leg al obl g ations

Summ ary of pag es

This document comprises a font cov er, an inside f ont cov er, p g es i and i,

p g es1 to 8 and a b ck cov er

This stand rd has be n up ated ( se cop rig ht d te) and ma hav e ha

amendments incorporated.This wi be indicated in the amendment ta le on the

inside f ont cov er

1 Scope

This International Stand rd specifies the lea and runout requirements for rol ed threa s for bolts, and

the inspection method to be used in case of dispute

It is also a plca le to other threa ed male p rts, used in aerosp ce construction, prov ided that it is

referenced in the definition document of the p rt

2 Definitions

For the purposes of this International Stand rd, the folowing definitions a ply

2.1

lea threa s

an area in which are located threa s incompletely formed during rol ng , beg in ing at the entering chamfer

of the threa

2.2

runout threa s

an area in which are located threa s incompletely formed during rol ng , betwe n the completely formed

threa s and the p rt which has not be n roled

2.3

c mpletely form ed threa

a threa , the profie of which ( ABC) is located, ov er an a ial distance of 1P, within the l mits specified in

the definition document for the threa ( Se Fig ure 1.)

3 Sym bols for thr ads

Fig ure 1

d = major diameter of the threa

d

2

= pitch diameter of the threa

d

3

= minor diameter of the threa

P = threa pitch

4 Lead and runout r quir m ents

4.1 General requirements

The flan s at the ro t of the incompletely formed threa s shal be joined b a ra ius or b two ra i and a

flat, that are smo th and dev oid ofa rupt to l marks This ra ius, or these ra i, and the ra ius r

( se Fig ure 3 to Fig ure 9) shal be not smal er than the minimum ro t ra ius specified for the complete

threa s in the definition document for the threa

4.2 Lea threa s

Se Fig ure 2

The pos ible profi e projection comp rator inspection shal be car ied out using a chart drawn in ac ord nce

with Fig ure 10

4.3 Runout threa s

4.3.1 No mal shank

Se Fig ure 3 and Fig ure 4

NOT Ov r the are Z,the thre d shal le within the lmits sp cified in the definition document for the thre d

Fig ure 2

Fig ure 3

The pos ible profie projection comp rator inspection shal be car ied out using a chart drawn in ac ord nce

with Fig ure 1

4.3.2 Pit ch d iamet er shank

Se Fig ure 5

The pos ible profie projection comp rator inspection shal be car ied out using a chart drawn in ac ord nce

with Fig ure 1

Fig ure 4

Fig ure 5

4.3.3 St epped shank

Se Fig ure 6

The pos ible profi e projection comp rator inspection shal be car ied out using a chart drawn in ac ord nce

with Fig ure 13

4.3.4 Screws t hreaded t o t he head and bol t s t hreaded t o a shoul d er

4.3.4.1 Pr otr ud ing hea d

Se Fig ure 7

The pos ible profi e projection comp rator inspection shal be car ied out using a chart drawn in ac ord nce

with Fig ure 1

Fig ure 6

NOT The radius r shal not enc o ch on the radius R

Fig ure 7

4.3.4.2 Fl ush hea d

Se Fig ure 8

The pos ible profie projection comp rator inspection shal be car ied out using a chart drawn in ac ord nce

with Fig ure 1

4.3.5 O versized b l t s ( for ex ample, bolts for rep ir )

Se Fig ure 9

NOT The radius r shal not enc o ch on the radius R

Fig ure 8

5 Inspection m ethod

The method is left to the dis retion of the manufacturer, prov ided that it ensures conformity with the

requirements g iv en in clause4

In case of dispute, the method b optical projection, defined hereafter, shal be used

5.1 Use ofthe charts

The charts shal be used in conju ction with a profie projection comp rator hav ing a mag nify ing power

equal to or g reater than× 20

5.2 Pro edure

5.2.1 Fo l ead t hreads

The inspection shal be car ied out using a chart drawn in ac ord nce with Fig ure 10

Rotate the bolt to find the fir t complete threa ( se Fig ure 1) nearest to the end of the shan which has

the threa c est and ro t not extending bey ond the lmits defined b the horiz ntal lnes

Then mov e the bolt horiz ntaly unti the rig ht flank of the a ov e threa coincides with l ne DE

Fig ure 10

5.2.2 Fo runout t hreads

The inspection shal be car ied out using a chart drawn in ac ord nce with Fig ure 1 to Fig ure 14

Fig ure 1

Fig ure 12

Rotate the bolt to find the last complete threa ( se Fig ure 1) nearest to the plain shan of the bolt which

has the threa c est and ro t not extending bey ond the l mits defined b the horiz ntal l nes

Then mov e the bolt horiz ntaly unti the left flan of the a ov e threa coincides with lne FG

Fig ure 13

Fig ure 14

ISO 3353:1992

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