Bsi bs a 305 1994 (1999) iso 7961 1994

BRITISH STANDARD BS A 305 1994 ISO 7961 1994 Bolts — Test methods Reproduced by IHS under l icense with BSI Uncontrol led Copy BS A 305 1994 This British Standard, having been prepared under the direc[.]

Bolts —

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 Stan ards

Bo rdan comes into efect on

1 Aug ust1 9

© BSI1 -1 9

The folowing BSI references

relate to the work on this

stan ard:

Commi e reference ACE/ 12

Draft for comment9 / 82 0 DC

ISBN 0 5 0 2 2 9 0

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 :

The Association of Electronic , Telecommu ications and Busines Equipment

Ind ustries

British Industrial Fastener Fed eration

Ministry of Defence

Society of British Aerosp ce Comp nies Ltd

Am endm ents is ued sinc publ cation

Commit e s responsible Inside font cov er

Fig ure 2 — Tensi e test — Position of the n t in relation

Fig ure 3 — Tensi e test — Up er an lower cup d etais 3

Fig ure 5 — Double shear test — Up er and lower blocks 5

Fig ure 6 — Stres cor osion test — Test cy linder ( principle) 10

Ta le 2 — Rates of load a pl cation — Double shear test 6

National foreword

This BritishStand ard has be n prep red u der the d irection of the Aerosp ce

Stand ards Pol cy Commit e It is identical with ISO7 61:19 4 A er ospa ce —

B ols — Te t method s, publ shed b the International Org anization for

Stand ard ization ( ISO)

Cros -referenc The Tech ical Commit e has rev iewed the prov isions of

ISO7 0 -1:19 6, to which normativ e reference is mad e in the text, and has

d ecided that they are ac epta le for use in conju ction with this stand rd

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

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 to1 , 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

This International Stand rd specifies test methods

for bolts for aerosp ce constructions

It is a pl ca le whenev er quoted in reference

The fol owing stand ard contains prov isions which,

throug h reference in this text, constitute prov isions

of this International Stand ard At the time of

publcation, the edition indicated was v ald All

stand ards are subject to rev ision, and p rties to

ag re ments b sed on this International Stand rd

are encourag ed to inv estig ate the pos ibi ty of

a ply ing the most recent edition of the stand rd

indicated below Member of IEC and ISO maintain

reg ister of cur ently v ald International Stand ards

ISO7 0 -1:19 6, Meta llc ma ter ia ls — Ver ifica tion

o sta tic u ia xia l te t ng ma chine — Pa r t1: Tensie

te tng ma chine

3 Tests

3.1 Tensi e test at am bient temperature

3.1.1 Ap aratus

3.1.1.1 Te t d evic ( se Fig ure 1)

The test dev ice shal be centred such that the stres

at four equi sp ced points arou d the test sample is

u iform within1 %, or such that the coa ial ty

betwe n the bolt an the clearance holes is les than

or equal to0,025mm to ensure the a pl cation of

the tensie load along the a is of the bolt

1)

Other ty pes of d ev ice ma be used prov id ed they

respect the req uirements of Fig ure 3

3.1.1.1.1 Cups, fixed or remov able, in conformity

with Fig ure 3, which specifies only fu ctional

req uirements

3.1.1.1.2 Te t n t ( fre -ru ning or self- ocking ) or

thr ea d ed pa r t ( as uming the role of a n t), of

suficient streng th to g uarante bolt fai ur e

3.1.1.2 Ta per ed spa cer , placed u der the head

during the test, when required b the procurement

specification or d efinition document to ev aluate the

efect of ang ularity The minimum clearance

betwe n the hole and the bolt shank shal

be0,13mm At least9 % of the bolt bearing area

shal be sup orted b the sp cer which shal hav e a

diameter suficient to sup ort the width ac os the

corner of the bolt The tolerance on the hole

diameter in the sp cer shal be mm

3.1.1.3 Wa sher s, used u der bolt head s or n ts only

in the case outlned in3.1.1.2

3.1.1.4 Tensie o compr es ive te t ma chine,

depending on the fixture, ca a le of a ply ing the

test loa s

3.1.2 Pr c dure

3.1.2.1 Assemble the bolt in the test dev ice( 3.1.1.1)

as shown in Fig ure 1 Instal the n t( 3.1.1.1.2) as

shown in Fig ure 2 Place the complete as embly

betwe n the load ing platens of the machine

3.1.2.2 Apply the loa specified in the procurement

specification or d efinition d ocument at the rate

specified in Ta le 1

1)

in a controled way

3.2 Double shear test

3.2.1 Ap arat us

Se Fig ure 4 andFig ure 5, the lat er only defining

fu ctional requirements

NOT 1 Totaly enclosed to an b t om blades ma b used as

an alternatv e

3.2.2 Pr c dure

3.2.2.1 Assemble the bolt into the lower p rt of the

g ui lotine The blend ra ius u der the hea an the

threa ed portion shal not be in contact with the

lower p rt of the g ui lotine ( se Fig ure 4)

3.2.2.2 Apply the loa required in the procurement

specification or d efinition d ocument at the rate

specified in Ta le 2, in a control ed way

I this loa is at ained without breakag e of the bolt,

the test ma be terminated

1)

1)

Calibraton re uirements:se ISO7 0 -1:1 8 an Anne A of this Internatonal Stan ard

+0,0

0

Fig ure 1 — Tensi e test — Test devic

Fig ure 2 — Tensi e test — Position of the nut in relation to

the com plete threa s (shank side)

Fig ure 3 — Tensi e test — Upper and lower cup detai s

Ta le 1 — Rates oflo d a pl cation — Tensi e test

Nom inal shan

diam ete

a

Rate

kN/ min

Nom inal shan

diam ete

a

Rate

kN/min

Nom inal shan

diam ete

a

Rate

kN/ min

3

4

5

6

7

8

10

5

9

14

20

27

3

5

1

14

16

18

20

2

24

8

1 0

14

18

2 0

27

320

27

3

3

3

3

4 0

5 0

6 0

7 0

8 0

a

For other shan diameter , b lts shal b tested at a lo ding rate, ac urate to± 1 %,of7 0N p r min te p r1mm

2

of nominal

shan c os -secton

Fig ure 4 — Double shear test — Test devic

Fig ure 5 — Double shear test — Upper and lower blocks

Ta le 2 — Rates of lo d applcation — Double shear test

3.3 Tension fatig ue test

3.3.1 A pp ratus

3.3.1.1 Te t d evic ( se Fig ure 1)

Univ er al joints an spherical seats shal not be

used in the test column The test d ev ice shal be

centred such that the stres at four eq ui sp ced

points arou d the test sample shal be uniform

within3% of the mean stres v alue

2)

Other ty pes of dev ice ma be used prov ided they

respect the req uirements of Fig ure 3

Test bolts shal not be re-used

3.3.1.1.1 Cups, fixed or remov ea le, in conformity

with Fig ure 3, which specifies only fu ctional

req uirements

3.3.1.1.2 Te t n t or thr ea d ed pa r t ( as uming the

role of a n t), with a heig ht g reater than or eq ual

to0,8D an of suficient streng th to ensure bolt

breakag e

NOT 2 Test n ts or thre ded p rts ma b re-used prov ided

that i me ts the dimensional re uirements an has not b en

damag ed b a pre ious test

For refere purp ses, only u used n ts or thre ded p rts shal b

used

3.3.1.2 Loa d mea sur ing system, of an ac uracy

within± 2 % of the a pl ed ma imum loa

2)

3.3.1.3 A utoma tic loa d ma inta ining system

3.3.1.4 Fixtur es, desig ned to incorporate the

features indicated in Fig ure 3

3.3.2 Pr c dure

3.3.2.1 Insta lla tion

Test bolts shal be as embled so that a minimum of

two an a max imum of thre complete thread s are

ex osed betwe n the n t or thread ed p rt ( 3.3.1.1.2)

bearing face and incomplete threa s on the shan

sid e

In the case of flush head bolts,the bearing betwe n

the bolt head an the loa ing cup in which it is to be

tested shal be u iform

There shal be no contact in the head -shan ju ction

area

3.3.2.2 Te t cond it ons

3.3.2.2.1 Tor que

There shal be no tensie stres due to torque or any

other instal ation procedure

3.3.2.2.2 Loa d level

The fatig ue test load s shal comply with the v alues

specified in the procurement specification or

definition d ocument

3.3.2.2.3 Fr equency

The f equency of the test shal conform with the

req uirements of the procurement specification or

definition d ocument The ma imum temperature of

the bolt during test shal not exce d5 °C

3.4 Stres durabi ity test of am bient

tem perature

3.4.1 App rat us

3.4.1.1 Fo tor que o elonga tion loa d ing

3.4.1.1.1 Ste l blocks or spa cer s, heat treated to

obtain a minimum Rockwel hardnes of4 HRC

3.4.1.1.2 Thr ea d ed pa r t, with suficient streng th to

withstand the ful tensi e streng th of the bolt being

tested

3.4.1.2 Fo exter na l loa d ing

3.4.1.2.1 Te t d evic , as specified in3.1.1.1

3.4.1.2.2 A d a pted fixtur e

2)

3.4.2 Pr c dure

Assemble the bolt in the test dev ice(3.4.1.2.1) and

a ply the loa specified in the procurement

specification or definition d ocument

Nom inal shan

diam ete

a

Rate

kN/ min

Nom inal shan

diam ete

a

Rate

kN/min

Nom inal shan

diam ete

a

Rate

kN/ min

3

4

5

6

7

8

10

10

18

27

4

5

7

1 0

1

14

16

18

20

2

24

16

2 5

28

3 0

4 0

5 0

6 0

27

3

3

3

3

8 0

9 0

1 20

1 4 0

1 7 0

a

For other shan diameter ,b lts shal b tested at a lo ding rate, ac urate to±1 %, of7 0N p r min te p r1mm

2

of double the

nominal shan c os -secton

2)

Calibraton re uirements: se ISO7 0 -1:1 8 an Anne A of this Internatonal Stan ard

For the torq ue load ing method, the loa is achiev ed

b torq ue tig htening to a pre-determined torq ue;

this torq ue ma be d etermined b formula or b

calbrating torque ag ainst a load cel as imi ating

the test as embly

3)

For the elong ation loa ing method , the load is

achiev ed b measur ing bolt extension; this

ex tension ma be d etermined b formula or b

calbrating extension ag ainst a loa cel

as imi ating the test as embly

3)

During the test, the loa ed portion of the bolt shan

shal hav e two ful thread s ex osed betwe n the

incomplete threa s on the shan side and the

bearing face of the thread ed p rt Ke p the bolt at

ambient temperature in the load ed cond ition for the

period of time specified in the procurement

specification or definition d ocument

At the en of this time, disas emble and ex mine

the bolt for the presence of c acks

Bolts suspected of hav ing c acks shal be sectioned

and mic os opicaly ex mined using×10

mag nification

Cracked or f actured test bolts constitute faiure of

the bolt

3.5 Inspe tion for g rinding burns

3.5.1 Pr c dure

3.5.1.1 Clea n

Remov e al foreig n mat er f om the bolts such as

g rease, dirt or oxide fi m

3.5.1.2 Weting te t

Rinse the bolts in cold water.I water breaks oc ur,

reclean the bolts

3.5.1.3 “Ni a l” etch

Immer e the bolts for2 min to2,5min in

a3% ( V/V) solution of nitric acid

( relativ edensity1,3 ) in ethanol, at ambient

temperature Ag itate the b th

3.5.1.4 R ins

Rinse the bolts for at least2min in ru ning water

at a temperature below25°C

3.5.1.5 B lea ching

Immer e the bolts for2 min to2,5min in

a5% ( V/V) solution of hy drochloric acid

( relativ edensity1,18) in ethanol, at ambient

temperature Ag itate the b th

3.5.1.6 R ins

Rinse the bolts for10s to3 s in ru ning water at a

temperature below25°C

3.5.1.7 Neutr a liza tion

Neutralzation ma be per ormed with either of the

folowing b ths:

3.5.1.7.1 A mmonia soluton

Immer e the bolts for3 s to6 s in a solution

of5 g /l of ammonia ( relativ e density0,9 ), at

ambient temperature

3.5.1.7.2 Soda soluton

Immer e the bolts for3 s to6 s in a solution

of5 g /l of sod at ambient temperature

3.5.1.8 R ins

Rinse the bolts for10s to3 s in ru ning water at a

temperature below25°C

3.5.1.9 D r y

Dry the bolts with fi tered compres ed air at

ambient temperature

3.5.1.10 Exa mine f r gr ind ing bur ns

These burns a pear as either white streaks

( untempered martensite) or d ark g rey ( zone of

ov ertempering ) on an ev en lg ht g rey b ckg rou d on

the sur ace of the bolts

3.5.1.1 De-embr it le

Car y out a ma imum of1 h of “ Nital”

etch( 3.5.1.3) de-embrit lement treatment on the

bolts at a temperature of13 °C±10°C

or19 °C±10°C for at least2 h, d epend ing on

whether the tempering temperature of the p rts is

les than or eq ual to20 °C or g reater than20 °C

NOT 3 After ble ching ( 3.5.1.5) an up to drying ( 3.5.1.9),

o eratons should b car ied out quickly to a oid o idaton This

o idaton builds up a chamois colour red cing contrast at a

defect Rinsing in ru ning water at a temp rature b low2 °C

prod ces a u iform lig ht g re colour on b lts wihout g rin ing

defects, inste d of a chamois colour for hig her temp ratures

3.6 Tensi e test at elev ted tem perature

3.6.1 Ap aratus

3.6.1.1 Te t d evic , as specified in3.1.1.1 Materials

and dimensional tolerances shal be consistent with

the temperature

3.6.1.2 Fur na ce, in which reg ulation and

thermocouples used shal determine, indicate an

control the temperature of the bolt ov er its entire

length within± 3°C to1 26 °C

4)

Thermocouples shal

— hav e the folowing ac uracy :

±1°C fom18°C to27 °C,

± 0,4% f om27 °C to1 26 °C;

3)

Formula : se A nne C

4)

Calibraton re uirements:se ISO7 0 -1:1 8 an Anne A of this Internatonal Stan ard

— be fit ed with ceramic insulator f om10mm

f om the ju ction to3 0mm outsid e the furnace,

an after, with an insulating material;

— hav e their hot spot clamped ag ainst the bolt so

as not to be afected b the ambient conditions;

— be at ached to each end of the bolt and, if

pos ible, in the mid dle

3.6.1.3 Tensie o compr es ive te t ma chine,

depend ing on the fixture, ca a le of a ply ing the

test loa s

3.6.2 Pr c dure

3.6.2.1 Mou t the bolt to be tested , fit ed with its

thermocouples,in the test d ev ice( 3.6.1.1), and place

this, with the furnace betwe n the platens of the

machine

3.6.2.2 Heat the furnace to the temperature

specified in the procurement specification or

definition document The minimum time to reach

this temperature shal be6 min per25mm of bolt

diameter

3.6.2.3 Maintain this temperature for3 min before

a ply ing the loa , then throug hout the test

3.6.2.4 Apply the loa specified in the procurement

specification or definition d ocument at the rate

specified in Ta le 1, in a control ed way

3.6.2.5 Record the bolt temperature for the ful

dur ation of the test

3.7 Stres rela ation test at elevated

temperature

3.7.1 App ratus

3.7.1.1 Te t d evic , as specified in3.1.1.1 Materials

and dimensional tolerances shal be consistent with

the temperature

3.7.1.2 Tensie te t ma chine, ca a le of ensuring

that the initial leng th of the bolt is maintained

u d er loa and to the nearest 0,0 5mm This shal

be ac ompl shed b means of an extensometer

con ected to a mechanism to a ply or remov e the

loa whenev er the initial leng th chang es

b 0,0 5mm

5)

The loa a pl ed to the bolt shal be measured

within±2% and recorded

3.7.1.3 Fur na ce, in which reg ulation and

thermocouples used shal d etermine, ind icate and

control the temperature of the bolt ov er its entire

leng th within± 3°C to126 °C

5)

The thermocouples shal

— hav e the folowing ac uracy :

±1°C f om18°C to27 °C,

± 0,4% fom27 °C to126 °C;

— be fit ed with ceramic insulator f om10mm

of the junction to3 0mm outside the furnace,

and after, with an insulating material;

— hav e their hot spot clamped ag ainst the bolt so

as not to be afected b the ambient conditions;

— be at ached to each end of the bolt, and if

pos ible in the mid le

3.7.2 Pr c dure

3.7.2.1 Mount the bolt to be tested, fit ed with its

thermocouples, in the test dev ice(3.7.1.1),and place

this,with the furnace ( 3.7.1.3), betwe n the platens

of the machine

3.7.2.2 Heat the furnace to the temperature

specified in the procurement specification or

definition document The minimum time to reach

this temperature shal be6 min per25mm of bolt

diameter

3.7.2.3 Maintain this temperature for3 min before

a ply ing the loa , then throug hout the test

3.7.2.4 Apply the loa specified in the procurement

specification or definition d ocument

3.7.2.5 Maintain the test temperature and bolt

leng th, and record loa ag ainst time for the specified

test duration Plot the stres rela ation curv e Use

the tensie stres area v alues specified in the bolt

procurement specification or definition document to

calculate the stres f om the recorder loa v alues

3.7.2.6 Record the bolt temperature for the ful

duration of the test

3.8 Stres cor osion test

CAUTION — I is re omm ended to take safety

pre autions to prote t f om explosive f acture

of the test b lt

3.8.1 App rat us

3.8.1.1 Te t cylnd er s, in conformity with Fig ure 6

which only specifies fu ctional req uirements, u les

otherwise specified in the procurement specification

or definition d ocument They ma only be re-used if

they are u d amag ed and completely f e f om

cor osiv e products

The materials ofthe comp nion test n t and

cy linder shal be those specified in the procurement

specification or d efinition document or of g alv anic

comp tibi ty with the bolt tested

3.8.1.2 Mea sur ing instr ument, ca a le of showing

v ariations in bolt leng th of104m with an ac uracy

of2,54m

5)

Calibraton re uirements: se ISO7 0 -1:1 8 an Anne A of this Internatonal Stan ard