Bsi bs a 301 1989 (2000) iso 8168 1988

BRITISH STANDARD AEROSPACE SERIES BS A 301 1989 ISO 8168 1988 Specification for Procurement of corrosion and heat resisting steel bolts with strength classification 1100 MPa and MJ threads Reproduced[.]

This Bri shStan ard, ha ing

b en pre ared u der the

directonof the Aerosp ce

Stan ards Policy Commi e ,

waspublished u der the

authoriyof the Bo rd of BSI

an comes into efect on

3 Octo er1 8

© BSI0 -2 0

The folowing BSI references

relate to the work on this

stan ard:

Commi e reference ACE/ 12

Draft for comment8 / 74 3 DC

ISBN 0 5 0 1 4 1 1

The prep ration of this BritishStand ard was entrusted b the Aerosp ce

Stand ard s Pol cy Commit e ( ACE/-) to Tech ical Commit e ACE/12 upon

which the fol owing bod ies were represented :

Civ il Av iation Authority ( Airworthines Div ision)

Electronic Eng ine ring Association

Ministry of Defence

Society of British Aerosp ce Comp nies Limited

Am endm ents is ued sinc publ cation

Amd No Date of is ue Comments

Commit e s responsible Inside font cov er

Fig ure 4 — Non-permis ible la s, seams and sur ace ir eg ularities 16

Fig ure 5 — Permis ible la s, seams an surace ir eg ularities 16

Ta le 2 — Qual fication testing requirements for bolt samples 8

Ta le 3 — Summary of q ual fication an ac eptance tests 9

Ta le 5 — Minimum tensi e and d ouble shear load s for q ual fication

Ta le 6 — Qual fication and ac eptance v alues for tension fatig ue test 10

Ta le 7 — Thread dis ontin ities — Ma imum depth of permis ible faults 10

Ta le 9 — Samplng plans for v isual inspection and inspection of

Ta le 10 — Sampl ng plans for the inspection of mechanical an

Ta le 1 — Varia le sampl ng for tensie an shear

Aerosp ce Stand ards Polcy Commit e , is id entical with ISO816 :19 8

“ A er ospa ce — Cor r osion- a nd hea t-r esist ng ste l bols wih str ength

cla ssifica tion1100MPa a nd MJ thr ea d s — Pr ocur ement spe ifica tion” publ shed

b the International Org anization for Stand rd ization ( ISO)

The Tech ical Commit e has rev iewed the prov isions of SO3 52,ISO3 5 and

ASTME1 2-8 to which reference is ma e in the text, an has d ecided that they

are ac epta le for use in conju ction with this stand ard It is env isag ed that a

BritishStand rd cor espond ing to ISO7 61 wi be publ shed

A British Stand ard d oes not purport to includ e al the neces ary prov isions of a

contract User of British Stand rd s are responsible for their cor ect a plcation

Com pl anc with a British Standard does not ofitself confer im m unity

f om leg al o l g ations

Cros - referenc s

Inte national Stand rd Cor esp nding BritishStand rd

ISO28 9-1:19 4 BS6 01 Sa mplng pr oc d ur es f r inspe ton by

a ttr ibute

Par t1:19 2 Spe ifica tion f r sa mplng pla ns ind exed by

a cc pta ble qua liy level (A QL) f r lot-by-lot inspe ton

( Tech icaly eq uiv alent)

ISO3 3 :19 7 BS5 32 Sta tistca l ter minology

Par t1:19 8 Glos a r y o ter ms r ela ting to pr oba biiy

a ndgener a l ter ms r ela ting to sta tist c

( Id entical

ISO5 5 -2:19 1 BS629 MJ thr ea d s f r a er ospa ce constr ucton

Par t2:19 2 Spe ifica tion f r d imensions fr bols

a ndn ts

( Id entical

Sum mary of pag es

This document comprises a f ont cov er, an insid e font cov er, p g esi andi ,

p g es1 to18, an inside b ck cov er and a b ck cov er

This stand rd has be n up ated ( se copy rig ht d ate) an ma hav e ha

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

inside f ont cov er

1 Scope and field ofappl cation

This International Stand rd specifies the characteristic and q ualty as urance requirements for bolts with

normal head s, ma e of cor osion- and heat-resisting ste l, hav ing a tensie streng th clas ification

of110 MPa an MJ threa s, and intended for use in aerosp ce construction

This International Stand ard a ples to bolts as d efined a ov e, prov ided that reference is ma e to this

International Stand ard in the product stand ard or definition d ocument

2 Ref r nces

ISO28 9-1, Sa mplng pr oc d ur es fr inspe ton by a ttr ibute — Pa r t1: Sa mplng pla ns ind exed by

a cc pta ble qua liy level (A QL) fr lot-by-lot inspe t on

1)

ISO3 52, Non-d estr uctve te tng — Penetr a nt inspe ton — Gener a l pr inciple

ISO3 5 , Non-d estr uctve te tng — Liquid penetr a nt inspe ton — Mea ns o ver ifica tion

ISO3 3 , Sta tistc — Voca bula r y a nd symbols

ISO5 5 -2, A er ospa ce constr ucton — MJ thr ea d s— Pa r t2: D imensions f r bol s a nd n ts

ISO7 61, Aer ospa ce — B ol s — Te t method s

2)

ASTM E1 2-8 , Sta nd a r d method s f r d eter mining a ver a ge gr a in size

3 Definitions

3.1

pro uction batch

q uantity of finished bolts man factured, using the same proces , f om a sing le material cast ( sing le heat

of aloy ), hav ing the same b sic p rt n mber an diameter, heat-treated tog ether to the same specified

cond ition and produced as one contin ous ru

3.2

inspe tion lot

q uantity of bolts fom a sing le production b tch with the same p rt n mber which completely defines the

bolt

3.3 Discontinuities

3.3.1

crack

rupture in the material which ma extend in any d irection an which ma be inter ry stal ine or

trans ry stal ine in character

non-metal c p rticles orig inating f om the material manufacturing proces These p rticles ma be

isolated or ar ang ed in string s

3.4

sim ple random sam pl ng

the taking of n items f om a population of N items in such a wa that al pos ible combinations of n items

hav e the same prob bi ity of being chosen

3)

3.5

critical defe t

a d efect that, ac ording to jud g ement and ex erience, is l kely to result in hazardous or u safe conditions

for indiv id uals using , maintaining or d epend ing upon the considered prod uct, or that is l kely to prev ent

perormance of the fu ction of a major end item

3)

3.6

m ajor defe t

a defect, other than c itical, that is lkely to result in a faiure or to reduce material y the usa i ity of the

considered product for its intended purpose

3)

3.7

minor defe t

a defect that is not lkely to red uce material y the usa i ity of the consid ered product for its intend ed

purpose, or that is a dep rture fom esta l shed specification hav ing l t le bearing on the efectiv e use or

operation of this product

in a sampl ng plan, a q ual ty lev el which cor esponds to a specified an relativ ely low prob bi ty of

ac eptance: for the purposes of this International Stand ard, a10% prob bi ty of ac eptance ( LQ

1) It is

the l miting lot q ualty characteristic that the consumer is wi ing to ac ept with a low prob bi ty that a

lot of this qualty would oc ur

)

3.10

ac epta le qual ty level (AQL)

a q ualty lev el which in a sampl ng plan cor espond s to a specified but relativ ely hig h prob bi ty of

ac eptance

it is the ma imum per ent defectiv e ( or the ma imum n mber of defects per h ndred u its) that, for

purposes of sampl ng inspection, can be considered satis actory as a proces av erag e

3)

4 Qual ty as ura nce

4.1 General

4.1.1 Appr val o manufacturers

The man facturer shal conform to the q ual ty as urance and a prov al proced ures in efect in the

pur haser’s cou try :the purpose of these procedures is to ensure that a man facturer has a q ual ty sy stem

an the ca a i ty for contin ous production of bolts comply ing with the specified q ual ty req uirements

The g ranting of an a prov al of the man facturer is a fu ction of the Certification Authorities, or their

a pointed representativ e, who ma be the prime contractor

4.1.2 Q ual ficat ion o b lt s

The purpose of qualfication inspections and tests of bolts is to check that the desig n and manufacturing

cond itions of a bolt al ow it to satis y the req uirements of this International Stand rd

The g ranting of q ualfication of a bolt is a fu ction of the Certification Authorities in the pur haser’s

cou try , or their a pointed representativ e, who ma be the prime contractor

3)

Defini on taken fom ISO3 3 :1 7 ( ISO3 3 is cur ently b ing rev ised b ISO/ TC6 , Ap lcaton of statstcal methods.)

4.1.3 Ac ept anc o b lts

The purpose of ac eptance inspections an tests of bolts is to check, as simply as pos ible, using a method

which is inex ensiv e and representativ e of actual conditions of use, with the uncertainty in erent in

statistical sampl ng , that the bolts satis y the req uirements of this International Stand rd

Acceptance inspections an tests shal be car ied out b the man facturer, or und er his responsibi ty The

man facturer is responsible for the qual ty of the bolts manufactured

4.2 Qualfication inspe tion and test conditions

Qual fication inspections and tests ( requirements, method s, n mber of bolts) are specified inTa le 1

They shal be car ied out on

— each ty pe and d iameter of bolt,

— 25 bolts selected f om a sing le inspection lot b simple rand om samplng

The test prog ramme ma pos ibly be red uced, or the qualfication of a bolt be g ranted , without inspection

or testing : any such decision shal be b sed on the results obtained on simi ar ty pes and d iameter of bolts

prov ided that the desig n and manufacturing conditions are id entical

The inspections and tests shal be repeated on any bolt if the man facturing conditions hav e chang ed

Ta le 2 ind icates the al ocation of bolt specimens for the inspections and tests

Qual fication inspections and tests are summariz d inTa le 3

4.3 Acc ptanc inspe tion and test conditions

Acceptance inspections and tests ( requirements, method s, number of bolts) are specified inTa le 1; they

shal be car ied out on each production b tch or inspection lot Bolts f om the b tch or lot to be tested shal

be selected b simple random samplng

Each bolt ma be submit ed to sev eral inspections or tests

The bolts to be subjected to destructiv e inspections or tests ma be those on which non-destructiv e

inspections or tests hav e be n car ied out

I a more string ent inspection is d eemed neces ary , al or p rt of the q ualfication inspections and tests ma

be per ormed during the ac eptance inspection an testing In this case, the number of bolts submit ed to

these inspections and tests is the same as that submit ed for q ualfication inspections and tests

Production b tches or inspection lots d eclared u ac epta le after the ac eptance inspections and tests shal

be submit ed for re-nspection or re-testing only after al defectiv e u its hav e be n remov ed and / or defects

hav e be n cor ected

Twice the normal sample siz shal be used for re- nspecting or re-testing the at ributes causing initial

rejection; the same ac eptance lev el shal be used

Acceptance inspections and tests are summariz d inTa le 3

The requirements of this International Stand rd are g iv en inTa le 1 and , u les otherwise specified, they

a ply to bolts rea y for use Unles otherwise specified, the test temperature shal be the ambient

temperature These req uirements complement the requirements of al other stand ard s or specifications

referenced in the prod uct stand ard or in the definition document of the bolt

Ta le 1 — Te hnical requirem ents and test m ethods

Clause

No

Characte is ic Te h ical r quir m ent

Inspe tion and tes

m etho

Q/Aa

S m ple siz

5.1 Materials In ac ord ance with the prod uct

stand rd or definition d ocument

As stated in the

material specification

5.2 Dim ensions In ac ord ance with the

req uirements of the product

stand rd or definition d ocument

Stand rd g aug ing Q

A2

Ta le 8

andTa le 9

5.3.1 Fo ging The head s of the bolts shal be

formed b a hot or cold forg ing

proces before heat treatment

In the case of hot forg ing , the

eq uipment shal be such that a

constant temperature of les

than1 0 0°C is g uarante d

throug hout the production b tch

The eq uipment used

shal be a prov ed

5.3.2 Heat t reatment The forg ed blanks shal be heat

treated to prod uce the properties

req uired b the prod uct stand rd or

definition document

No blank shal be heat treated more

than twice The heat treatment

media or atmosphere shal not cause

any sur ace contamination except as

permit ed b 5.5.3

5.3.3 Machining The amou t of material removed

fom the bearing surace of the hea

and the shan of the heat-treated

blan s shal be as lt le as

practica le consistent with the

remov al of sur ace contamination,

production of a smo th sur ace an

maintenance of optimum g rain flow

arou d the u der-head fi et ra ius

as shown inFig ure 1

Se 5.5.1

5.3.4 Cold r l ing The fi et ra ius shal be cold roled

after heat treatment an machining

so as to remove al v isual sig ns of

machining and to c eate supericial

cold working ; this ma cause

distortion which shal not exce d

the v alues shown inFig ure 2; this

requirement is not a pl ca le to

fuly threa ed s rews or bolts with

a nominal d iameter les than MJ

Se 5.5.1

5.3.5 Threads To be formed b a sing le rol ng

proces after al heat treatment

5.3.6 Sur ac

r ughne s

In ac ord ance with the prod uct

stand rd or definition d ocument

V isual comp rison

Q=qualificaton insp cton an test con i ons ( se 4.2)

A=prod cton ace tance test con i ons ( se 4.3)

Table 1 — Te hnical requirem ents and test m etho s

Clause

No

C aracte is ic Te h ical r quir m ent

Inspe tion and tes

c) threa ed -to-hea bolts of ov eral

length les than3D or bolts hav ing an

ov eral leng th les than18mm

In such cases, ac eptance shal be b sed

on the results f om tests b r of the same

material, heat-treated with the same

proces cy cle

A5

The g rip leng th shal not be shorter than

twice the nominal shank d iameter for

protruding hea bolts or shorter than2,5

times the nominal shank diameter for

cou ter u k hea s

A5

Ta le 10,

column B

Unbroken bolts shal be rendered

u usa le

Unles otherwise specified , fatig ue tests

shal not be car ied out on the fol owing :

a) bolts with d ri ed shanks;

b) bolts of threa siz smaler

than5mm;

c) bolts hav ing a g rip leng th of les than

twice the diameter

5.5 Metal urg ical

pro erties

Ta le 1 — Te hnical requirem ents and test m ethods

Flow lnes in the fi let area

immed iately below the

surace shal closely conform

to the fi et contour

( se Fig ure 1)

Se Fig ure 1 for breaks in flow

l nes

I there is d oubt a out the

ac epta i ty of the g rain flow

or fi et work efect, the

ac epta i ty shal be decid ed

b the results of the

ac eptance fatigue test

Specimens shal be taken

f om the finished bolt

( se Fig ure 6) The sections

to be ex mined shal be

subjected to an a propriate

mac os opic etchant

Mac os opic ex mination

of a long itudinal section at

a suita le mag nification

( X 10 to X 20)

Q

AA

The grain flow shal be

contin ous an shal fol ow

the g eneral threa contour

with the ma imum density at

the bot om of the ro t ra ius

( se Fig ure 3)

Mac os opic ex mination Q

A4

Ta le 10,

column B

5.5.3 Micr structure The mic ostructure shal be

f e f om ov erheating and

aloy seg reg ation which is

l kely to afect the mechanical

or phy sical properties of the

bolt

The sections to be

ex mined shal be

subjected to an a propriate

mic os opic etchant

Mic os opic ex mination at

a mag nification of X 10

Q

A4

Ta le 10,

column B

5.5.4 G rain size The g rain siz of the finished

bolts when comp red with

plate I in ASTM E1 2-8

shal not be coar er than5

I olated g rains not exce d ing

a mean d iameter

a

of0,23mm

are ac epta le

Mic os opic ex mination

at a mag nification of X 10

Q

A4

Ta le 10,

column B

5.5.6 Dis ont inuitie The bolts shal not show any

dis ontin ity equal to or

g reater than the lmitations

specified in this International

Stand rd ( se Ta le 4) Care

shal be exer ised to av oid

confusing c acks with other

dis ontin ities

Cracked bolts an those

hav ing d is ontinuities

transv er e to the a is ( i.e.at

an ang le of more than10° to

the long itudinal ax is) shal be

rejected an destr oy ed

Penetrant flaw detection in

ac ord nce with ISO3 52

Table 1 — Te hnical requirem ents and test m etho s

Clause

No

C aracte is ic Te h ical r quir m ent Inspe tion and tes m etho Q/A S m ple siz

5.5.6.1 Hea d a nd sha nk Se Ta le 4 for the lmits of

v alues to be inc eased b

half the diference betwe n

the actual measured

diameter and the minimum

external thread diameter

( se ISO5 5 -2);

— a slg ht ir eg ularity in

the form of the c ests in

relation to the b sic profi e

is ac epta le ( se Fig ure 5)

identification

Marking in ac ord nce with

the product stand ard or

definition document

Bolts to be “ packag e-marked”

shal be p cked and identified

in ac ord ance with5.7.1

and5.7.2

A25

Ta le 8

andTa le 9

5.7.1 Packaging The bolts shal be p cked in

such a wa as to prev ent any

d mag e or cor osion oc ur ing

in the cour e of hand ling ,

transportation and storag e

Each b sic p ckag e shal only

contain bolts with the same

p rt n mber an the same

inspection lot number

5.7.2 Label ing Each b sic p ckag e shal

car y a la el on which the

complete p rt n mber,

quantity , production b tch

number and inspector’s stamp

hav e be n leg ibly record ed

Ta le 2 — Qual fication testing requirem ents for b lt sam ples

Hea -to-shan

g rain flow and

fi let work efect