amt – 100 aircra material, processes &...
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AMT–100Aircra,Material,Processes&
HardwareChapter5
MetalProper<es• Hardness-Thepropertyofamaterialthatenablesittoresistpenetra<on,wearorcuDngac<ons.
• Strength–Theabilityofamaterialtoresistdeforma<on(beingdeformed)
• Malleability-Thecharacteris<cofamaterialthatallowsittobestretchedorshapebybea<ngofahammerorpassingthroughrollerswithoutbreaking.
MetalProper<es• Duc<lity-Thepropertywhichallowsmetaltobepermanentlydrawn,bent,ortwistedintovariousshapeswithoutbreaking.
• Elas<city-Thecapabilityofamaterialtobestretched(deforma<on)andtorecoverit'ssizeandshapea,erit'sdeforma<on.Thepointatwhichpermanentdeforma<onoccursistheyieldpoint.
• Toughness-Thepropertyofthemetalwhichallowsittobedeformedwithoutbreaking.TheoppositeofbriPleness.
MetalProper<es• BriPleness-Thepropertyofamaterialtobreakwhenbentordeformed.Itistheresistancetochangeintherela<veposi<onofthemoleculesinthematerial.
• Conduc<vity-Theabilityofamaterialtotransferheatorelectricity
• ThermalExpansion–Thecontrac<onandexpansionofmaterialastheresultofhea<ngorcooling.
FerrousMetals• Ferrousmetalisonethatcontainsiron• Pureironistooso,foraircra,use
! Addcarbontoironandyougetsteel
• SAE-SocietyofAutomo<veEngineers
• SAEfour-digitnumberingsystemforiden<fyingsteel! Firstdigit:basicalloyingelement
! Seconddigit:thepercentageofthebasicelementinthealloy
! Thirdandfourthdigits:percentageofcarboninthealloyin1/100ofapercent
FerrousMetals• Example:SAE1020-steelthatislow-carbonsteelthatcontains0.20%carbon
• Maximumamountofcarbonisjustover1%! Morecarbon,harderandmorebriPle
• 1XXX–Carbonsteel! SAE1010to1030
• 0.10to0.30%carbon• So,• Canbesurfacehardened
FerrousMetals• 1XXX–Carbonsteel
! SAE1030to1050–medium-carbonsteels
! SA1050andgreater–high-carbonsteel
• 2XXX–Nickel! SAE2330steelisusedforaircra,bolts,cableterminals,keys,clevises,andpins.
• 3xxx-Nickel-chromiumsteel
FerrousMetals• 41xx-Chrome-molybdenumsteel
! 4130verycommoninaircra,parts
• 6xxxChrome-vanadiumsteel! Commonfortools
CRES• CorrosionResistantsteel• Stainlesssteel• 10+%ofchromium
• 200thru400series• Usuallynon-magne<c
AluminumAlloys• Aluminumalloyfour-digitiden<fica<onsystem:
! Firstdigit-Alloytype
! Seconddigit-Modifica<onofalloy! Thirdandfourthdigits-Purityofaluminum
• 1100–purealuminum
• 2XXX–Copperischiefalloy! Strongbutcorrodeseasily! 2117–rivets,2024–sheetmetal! Can’tweld
AluminumAlloys• Cladaluminum(Alcad)–averythinlayerofpurealuminumappliedtothesurfaceofsheetaluminum! Protectagainstcorrosion
• Purealuminumcreatesaluminumoxidewhenexposed• Aluminumoxideisawhitefilm
• Protectstheremainingaluminum• Isaninsulator
! Easytoscratch! Slightlylessstrengththananuncladsheetofthesamethickness
MagnesiumAlloys• Light&Strong• Highlysuscep<bletocorrosion• Tendencytocrack• Burns
! Usedry-powderfireex<nguisher! Don’tusewater
Titanium• Highstrength• Corrosionresistant• Lightweight• Needspecialtoolstowork,machineorweld
PureCopper• Goodconduc<vity–heatandelectricity• Corrosionresistant• BecomesbriPlewhenworkhardened
• Alloys! Beryllium! Zinc–makesbrass! Tin–makesbronze
! Aluminum! Manganese
Nickel• Usedforhighstrengthandhightemperatureapplica<ons
• Monel
• Inconel
IronCrystallineForm
IronCrystallineForm
MetalHeatTreatment• Steelhasacrystallinestructure• Thearrangementofatomsinsteel’scrystallinestructuredeterminethesteel’shardness
• Theprocessesofhea<ngandcoolingareusedtocontrolnatureofthestructure
• Thesamehea<ngandcoolingprocessescanbeusedtocontrolhowthealloyingelementschangethesteel’sstructure
MetalHeatTreatment• Cri<calTemperature–Thetemperatureatwhichtheinternalstructuretakesacrystallineform! Lowerthanmel<ngpoint
• Tocontrolthesteel’shardness,thesteelisraisedtoabovethecri<caltemperatureandthancooledtolockinthecrystallinestructure
• Thefasterthesteeliscooled! Themoredensethecrystallinestructure! Themorehard(harder)
! ThemorebriPle
MetalHeatTreatment• Thecoolingprocessiscallquenching• Quenchingliquidsandrates
! Brine(water&salt)–veryfast
! Water–fast! Oil–slow
• Canstartaflashfire! Polymerandwater–precisioncontrol! Salts–precisioncontrol
• Producesmoreconsistentresultsbetweeninteriorandsurface
• Highspeedquenchingcancausecracking
MetalHeatTreatment• Normalizing
! Forging,working,rolling,machiningandweldingcanleavestressesinametalstructure
! Normalizingrelievesthestresses
! Heattoabovecri<caltemperatureandthencooledslowlyinair
MetalHeatTreatment• Annealing
! Producesafine-grain,so,,duc<lemetalwithoutinternalstressesorstrains
! Canproducetheloweststrengthsteel
! Heatabovecri<caltemperatureandletitsit(soakatthattemperature
! Slowlycooledinatemperaturecontrolledfurnace
SteelTemperatureRanges
Temperaturerangesforheattrea<ngsteelalloys.
MetalHeatTreatment• Tempering-AformofheattreatmentinwhichsomeofthehardnessandbriPlenessisremovedfromametalthathasbeenhardenedbyheattreatment! Temperingtemperaturesarelowerthanthecri<caltemperature
! Temperingproceduresincludeaspecifictemperatureand<me
MetalHeatTreatment
Temperingtemperaturesforvarioussteelalloystoobtaintheindicatedtensilestrength.
ToolTempering
Temperingofsmalltoolsbyobservingthecoloroftheoxidesthatformwhenthesteelisheated.
CaseHardening• Casehardening-AtypeofmetalheattreatmentinwhichthesurfaceofthemetalishardenedandmadebriPlewhilethecoreofthematerialremainsstrongandtough! Usuallydonewithlowercarbonsteel! Thehardenshellisverythin
• 0.01”to0.06”! Thehardeningprocesscanbeappliedtoonlyspecificpartsofanobject
CaseHardening• Nitriding-Amethodofcasehardeningsteelbyhea<ngitinanatmosphereofammonia.Thenitrogenintheammoniareactswiththesurfaceofthesteeltoformextremelyhardnitrides! Doesn’tchangethedimensionofthepart! Causeslessdistor<onthanothertypesofcasehardening
CaseHardening• Carburizing-Casehardeningprocessinwhichaddi<onalcarbonisinfusedintothesurfaceofalow-carbonsteel.! Surfaceisheatedandthenexposedtocarbon
! CarboncancomefromCO2,sootorcoke! CanbemadeinafurnacefilledwithCO2
ColdWorking• Plas<cDeforma<on-Amaterialundergoingnon-reversiblechangesofshapeinresponsetoappliedforces
• ColdWorking-Thestrengtheningofametalbyplas<cdeforma<onatlowtemperatures! Alsocalledworkhardeningorstrainhardening! Coldrollingisaformofcoldworking
• Wrought-beatenoutorshapedbyhammering
Forging• Forging–Theprocessbywhichmetalisheatedandisshapedbyplas<cdeforma<onbysuitableapplyingcompressiveforce! Usuallydonewithpowerhammerorpress
! Refinescrystalgrainstructure• Improvesstrength,duc<lityandtoughness• Canorientdirec<onofgrainflowtothatoftheprinciplestressesencounteredinactualuse
• Video1• Video2• Video3
Cas<ng• Cas<ng–formingbymel<ngthemetalandpouringintoamoldofthedesiredshape
• Video1,Video2• Lesscontrolovergrainandcoolingprocess• LowerstrengthandmorebriPlethanforgedproducts
Extrusion• Extrusion–forcingametalthroughanopeninginadie,thuscausingthemetaltotaketheshapeofthedie
• Video
HeatTrea<ngAluminumAlloys• CalledSolu<onHeatTrea<ng• Mustbequenchedimmediatelyinwater
! Createssmallcrystals• ThesmallerthecrystalsthebePer• Quenchasfastaspossible
! Delayinquenchingcausesthecrea<onoflargercrystals• Largercrystalscauseintergranularcorrosion
! Intergranularcorrosion-Corrosionthatformsalongthegrainboundariesinapieceofmetal.
IntergranularCorrosion
Intergranularcorrosioncanstartonthesurfaceandprogressthroughthemetal,followingthegrainboundaries.
IntergranularCorrosion
IntergranularCorrosion
HeatTrea<ngAluminumAlloys• Aluminumdoesn’treachfullstrengthimmediatelya,erquenching
• Thealuminumhardenswithage! Called“aging”or“agehardening”! Canhappeninminutes,hours,daysoryears
! Remember“icebox”rivets(D&DD)
Ar<ficiallyAgeHardeningAluminum• CalledPrecipita<onHeatTreatment• Acceleratetheprocessofagehardening• Heldatatemperature,muchlowerthanthatusedforsolu<onheattreatment,forupto24hoursandthenremovedfromtheovenandallowedtocooledins<llair
• Increasesthestrengthandhardness• Reducesduc<lity• Makeshardertobendandform
AluminumTreatment• Annealingisusedtoso,enaluminum
! Usedtoso,enaluminumwhenworkingor“pounding”metalintoshape
• AluminumisNOTnormalized! Onlysteel
• Onceclad,sheetmetalisnotheattreated! Thepurealuminumlayerwillcontaminateinnerlayer
AluminumAlloyTemperDesigna<ons• Temper-hardened• F–Fresh/rawaluminum
! Nevercoldworked,heattreated,orannealed
• O–Annealed• T–Heattreated/hardened• H–Work/strainharden
AluminumAlloyTemperDesigna<ons
Temperdesigna<onsofaluminumalloys.
HardnessTes<ng• Twomethods:
! Rockwell
! Brinell
• Rockwell! Measuresthehardnessofametalbymeasuringthedepthofpenetra<onofaspecialpenetratorunderaspecifiedload
! So,metalsuseahardenedsteelball! Hardmetalsuseadiamondcone! Fourscales:AthruD
• BandCthemostcommon
RockwellTes<ng
RockwellTes<ng• Video
BrinellHardnessTes<ng• Hardnessofthematerialismeasuredbythediameteroftheimpressionmadebya10-mm-diameterhardenedsteelballforcedintothematerialbyahydrauliccylinder
BrinellHardnessTes<ng
A.Brinellhardnesstester.B. MicroscopicviewofimpressionmadebyaBrinelltester.
Figure 7-9.
Wood• Onceaverypopularmaterial• Lightandstrong• Hasproblemswithwaterdecay
• Becarefulwhichglueisusedforrepair! Theglueusedtomanufacturetheaircra,maynolongerbeacceptable
! AC43-1BrecommendsResorcinoladhesive(resorcinol-formaldehyderesin)
! AC43-1Balsorecommendsepoxybutdoesn’tindicatewhichone
Plas<cs• Thermoplas<cresins
! So,enedbyheatandhardenedwhencooled
! Usedforwindshieldsandsidewindows! Celluloseacetate
• Yellowswithage• Dissolveswithacetone
! Acrylicresins• Tradename-Plexiglas,Lucite,andPerspex
Plas<cs• ThermoseDngResins
! Willnotso,enwhenitisheated,anditwillcharandburnbeforeitmelts
! Plas<ctrim
! Epoxy
Fabric• CoPon
! Decayseasily
! Usedforrestora<onprojects
• PolyesterhasreplacedcoPon! TradenameDacronorCeconite
• Severalcoveringsystemsavailabletoreplacenitrate/butyrate(dope)! NeedanSTCtoapply
Composites• Fabricsheldtogetherwithglue
! Strengthprovidedbyfabricnotglue• Usetheminimumamountofglue
• Glues! Epoxy
• Twopartresins• Mixra<oiscri<cal
! Polyesters• Mixwithacatalyst
• Mixra<oislesscri<cal• Notasstrongepoxy
Composites• Fabrics
! Fiberglass• Strongandlight• Non-conduc<ve• Rela<velyinexpensive
! Kevlar• Strongandstretches• Non-conduc<ve
Composites• Fabrics
! Carbon• Verystrong
! Strongerthanfiberglass
• Conduc<ve! Radioinstalla<onmoredifficult
• Cancausecorrosionproblemswithmetals
• CanbebriPle• Expensive
• Theindustryiss<lldevelopingmethodstorepairdamage
• Agingproper<esares<llunknown
Rubber• Natural–fromtrees• Synthe<c• Notallrubbersareequal
! Matchtherubbertotheapplica<on! RTFM
Aircra,Hardware• AsanA&P,youmustinsurethatanaircra,containsonlythehardwarespecifiedbythetheaircra,manufacturer
• Na<onalhardwarestandards! AN–AirForce-Navy
! MS-MilitaryStandard! NAS-Na<onalAerospaceStandards
ThreadFit• Standards
! UnifiedStandard–3classes• A–screworexternalthread• B–nutsorinternalthread
! American(Na<onal)Standard–4classes• Class-1-fitisaloosefit.Usedforeasytoremoveapplica<on
• Class-2-fitisafreefit.Itisusedforsomemachinescrews.• Class-3-fitisamediumfit.Itisusedforalmostallstandardaircra,bolts.
• Class-4fitisaclosefit,thatrequiresawrenchtoturnthenutontothebolt.
FastenerTorque• Followthemanufacturer’srecommenda<ons
! OrAC43-13-1BTable7-1
• Unlessotherwisespecified,torquevaluesfor<ghteningaircra,fastenersarespecifiedwiththreadsingoodcondi<onandtheymustbecleananddry! Iflubrica<onisspecified,usetheexactlubrica<oncalledforandtheexactamount
FastenerTorque• Methods:
! Torquewrench• Remembertoaddthetorquerequiredtoturnaloosefastener
! Nut-rota<onmethod• Tightenedun<lfastenerissnug,thenturnedaspecificnumberofturnsor“faces”
! Bolt-stretchmethod• Tightenedun<lthefastenerisstretchedaspecifiedamount
TorqueRa<os• 1in-oz=28.35gram-in• 1in-lbs=16in-oz• 1foot-lbs=12in-lbs
Aircra,BoltIden<fica<on
Aircra,boltiden<fica<on.
BoltMarkings• Crossorasterisk-nickelsteel• Singledash-corrosion-resistantsteel(CRES)bolt• Twodashes-aluminumalloy
• Trianglesurroundingthecrossorasterisk-close-tolerancebolt! Hasnogripcoa<ng
Bolt Length
Shank
Chamfer
AN3thruAN20• Hexheadboltfortensionorshear• Grip–por<onwithnothread
! Shouldbethesamelengthasthethicknessofthematerialbeingfastenedwiththebolt
• Shank–Includesthethreadedpor<on• Chamfer-taperedend
• Length-boPomoftheheadtothechamfer
• Finethread–UNF-3A• NewstandardisNASM3thruNASM20
AN3thruAN20• Example:AN4H6
! StandardBolt
! AN4–1/4”diameter! H-steelwithholeinhead! 6–3/4”long
! NoA-holeinshank
AN3thruAN20• AN(Diameter)(Material)(HeadHole)(Length)(ShankHole)
• AN• Diameter-3thru20-in1/16’s-3/16through11/4(20/16)
• Material! “-”NickelSteel2330(SilverisCadmium1,GoldisCadmium2)
! “C”–CRES
! “DD”–Aluminum
• H-holeinhead
AN3thruAN20• Lengthin1/8’s
! 3thru7–3/8thru7/8
! No8or9! 1”andabove–firstdigit–inches,second–1/8’s
• 'A'isnoshankhole,Nothingisholeinshank
AN3thruAN20• Example:AN4H6
! StandardBolt
! AN4–4/16”-1/4”diameter! H-steelwithholeinhead! 6–6/8”-¾”long
! NoA-holeinshank
• TestExamples:! AN5-7! AN14C7A
! AN16H10! AN7DD7A
BoltInstalla<on• Whenpossible
! Installheadfacingforward orInstallheadfacingup
! Lesslikelytofallout
• AN3isreallyaNO.10-32screwsize! Biggerthan3/16”
BoltInstalla<on–AC43-13-1B• Overtheyears,somefastenersspecifica<onshavebeenchanged.Forthisreason,itisrecommendedwhenmakingrepairstoanaircra,,whoseoriginalhardwareisbeingreplaced,thatyoumustfirstmeasuretheboltbeforeordering,ratherthanrelyingonthepartsmanualforiden<fica<on.
• Themaximumcombinedheightofwashersthatshouldbeusedis1/8inch.Thislimitstheuseofwashersnecessarytocompensateforgrip,uptothenextstandardgripsize.
BoltInstalla<on–AC43-13-1B• Allboltinstalla<onswhichinvolveself-lockingorplainnutsshouldhaveatleastonethreadoftheboltprotrudingthroughthenut.
• Lockorsafetyallboltsand/ornuts,exceptself-lockingnuts.DonotreusecoPerpinsorsafetywire.
ClevisBolt
Aclevisboltisdesignedtotakeshearloadsonly,andshouldneverbeusedwhereatensileloadisimposed.
AN21thruAN37• Clevisbolt• Forshearloadsonly• Normallyinstalledsothattheyarelooseandfreetorotate
• Whenrota<onispossible,ashearcastlenutshouldbeinstalledandacoPerpinshouldbeusedtosecurethenuttothebolt.
• Whenaclevisboltisusedtosecureafork-endcableterminal,thenutshouldbe<ghtenedun<litissnug,buttheremustbenostrainonthefork.
AN21thruAN37• Steelonly• Usesiden<fiernumbersimilartoAN3thruAN20
• Diameter! AN21–NO.6-40screwsize! AN22–NO.8-32screwsize! AN23–NO.10-32screwsize
! NoAN36,AN37is1¾”long! AN24thru35
• (AN#-20)X1/16! e.g.AN24–(24–20)X1/16=4/16=1/4"
AN21thruAN37• Materialisalways“-”
! Steel
• Lengthin1/16”! Nospecialdesigna<onforover15/16”
• Add'A'totheendfornoshankhole.Nothingisholeinshank
DrilledHeadBolts• AN73thruAN81–DrilledHeadBolts
! Threadtype&material• “-”–Steelwithfinethread• “A-”–Steelwithcoarsethread
! Diameterin1/16”• AN#-70
! e.g.AN75–70=5/16
! Lengthis1/8”• Doubledigitlikestandardbolts
! Noshankholeandno“A”used
DrilledHeadBolts• AN73thruAN81–DrilledHeadBolts
! e.g.AN75-10is5/16”diameter,steel,finethread&1”long
! e.g.AN75A-10is5/16”diameter,steel,coarsethread&1”long
DrilledHeadBolts• SupersededbyNASM20073&NASM20074
! NASM20073issteelwithfinethread
! NASM20074issteelwithcoarsethread! Bothuse–dd-llforsizing
• ddistwodigitdiameterin1/16”
• llistwodigitlengthin1/8”-likestandardbolts! e.g.NASM20073-05-10issteel,finethread,5/16”diameter&11/4”(10/8)long
! e.g.NASM20074-05-10issteel,coarsethread,5/16”diameter&11/4”(10/8)long
DrilledHeadBolts• Finethreadfornutsorsteelparts• Coarsethreadforaluminumormagnesiumcas<ngs
CloseToleranceBolts• AN173thruAN186• Noexternalcoat
! Protectedbyoilorgrease
• Steelonly• NumberingsystemthesameasAN3thruAN20exceptsubtract170fromAN#! e.g.AN175–170=5or5/16diameter
• HeadMarkings–triangle,trianglewithacrossinside,trianglewithasteriskinside
Nuts
Commonlyusednon-self-lockingaircra,nuts.
Nuts• AN310–CastleNut&AN320–ShearCastleNut
! NowcalledNASM310&NASM320
! Material• “-”–Steel• D–Aluminum• C–CRES
! Diameterin1/16”–finethread! AN320areusedforshearapplica<onsonly! TorquetominimumseDng.Ifshankholedoesn’tlineup,torqueuptomaximumseDng• Changewashersifshankholedoesn’tlineup
Nuts• AN315–PlainNut
! NowcalledNASM315
! Material• “-”–Steel• D–Aluminum• C–CRES
! Diameterin1/16”–finethread! “R”isrighthandthread,“L”isle,handthread
• RmaybeomiPed
! e.g.AN315-8RorAN315-8
Nuts• AN316–CheckNut
! NowcalledNASM316
! Material• “-”–Steel• C–CRES
! Diameterin1/16”–finethread! “R”isrighthandthread,“L”isle,handthread
• RmaybeomiPed
! e.g.AN316-8RorAN316-8
! Usetolockothernuts
Nuts• AN365–SelfLockingNut
! NowcalledMS20365
! Material• “-”–Steel• D–Aluminum• B–Brass
! Diameter&TPI–ddPordP• dorddisdiameterin1/16”
• PisTPI(coarsethreadfor#4thru#8screwsizes)• e.g.624is3/8-24• Screwsizes440,632,832&1032
Nuts• AN365–SelfLockingNut
! Insertmaterial• A-non-metallic–lowtemperatureapplica<ons• C–metallic–hightemperatureapplica<on
• Nodesigna<on–EitheranAorCcanbeused! Theinserthasasec<onthathasnothreads,thisiswhatlocksthebolt
! Selflockingnutsshouldnotbeusedwithfastenersthatrotate
! Ifyoucanturnaselflockingnutwithyourhand,itiswornout.
Nuts• AN363(MS20363)–Hightemperatureselflocking
• AN364(MS20364)–Thin(shear)selflocking
• AN356(MS27151)–PalNut! Nutmadeoutofpressedsheetmetal! TrademarkPalnut™
! AN356andMS27151isdifferentnumberingsystem
Nuts• AN350–Wingnuts• MS21078,MS21080,MS21081areluganchornut
• MS21079isachannelnut
TinnermanSpeedNut
PlainWashers• AN960–Plainwasher
! NowcalledNAS1149
• AN970-PlainWasherLargeArea! NowcalledNASM970
• Availableinavarietyofmaterialsandcoa<ng! Usecorrectmaterialandcoa<ngpreventcorrosionproblems
• Availableisstandardandlight(thin)thicknesses! Lightwashercanbeusedtoadjustcastlenutposi<on
PlainWashers• Providesasmoothbearingsurface• Protectssurfacefromgalling&corrosion
! Mustbeusedwhenusingalockingwashers
• Shouldbeusedundereveryboltheadandnut• Whenusinglockwasher,theordershouldbe:
! Ma<ngsurface! Plainwasher
! Lockwasher! Nut
LockWashers
LockWashers• AN935–Splitlockingwasher
! NowcalledMS35338
! Steel! AN935hasdifferentthicknesses,MS35338doesn’t
• AN936–Starwasher! TypeA–internalteeth
! TypeB–externalteeth! Availableinsteelandbronze! Singleuse
WhenNottouseaLockWasher• Withfastenerstoprimaryorsecondarystructure• Withfastenersonanypartoftheaircra,wherefailuremightresultindamageordangertotheaircra,orpersonnel
• Wherefailurewouldpermittheopeningofajointtotheairflow.
• Wherethescrewissubjecttofrequentremoval
WhenNottouseaLockWasher• Wherethewashersareexposedtotheairflow• Wherethewashersaresubjecttocorrosivecondi<ons
• Theaboverulesaregoodguidelineswhennottouselocknuts
CoPerPins• AN380–SteelcoPerpin• AN381–CREScoPerpin• NowcalledMS24665
• Checkdatasheetfordashnumberingsystem
• Diametershouldbethelargestsizetofitintofastener’shole
• Topreventinjuryduringanda,erpininstalla<on,theendofthecoPerpincanberolledandtucked.
CoPerPins• Don’treusecoPerpins• Don’tuseautomo<veorhardwarestorecoPerpins
CoPerPins–43.13-1B
Screws• Types:
! Structural
! Machinescrews! Self-tapping
• Structuralscrew! Muchlikestandardboltbutwithscrewhead
! Fineandcoarsethread
• Machinescrews! Usuallynogrip! Steel,CRESorbrass
! Nousedforprimarystructure
Screws• Countersunk/flatheadmachinedandstructuralscrewuse100°countersink
• Fillisterheadscrewsmayhaveasafetywirehole
ScrewHeads
FillisterHead
ScrewHeads
ScrewHeads
WasherHeadScrews
SelfTappingScrews• AlsocalledPKorParkerKalonscrews• 82°countersunk• Usedforsheetmetalandinspec<onpanel
• UsedwithTinnermannuts
• Non-structural
SelfTappingScrews
DzusFastener
Dzus™Fastener
Dzus™Fastener
Dzus™Fastener
Dzus™Fastener• Lengthspecifiedin1/100(0.01)inchincrements• Diameterspecifiedin1/16inchincrements
• Headmarkingsarebodydiameter,typeofhead,andlengthofthefastener
• Reten<ongrommet/collarcommonlycomeloose
CamLockFastener
CamlockFastener
Camlockfastener:explodedview.
AirlocFastener
BlindRivets• Canbeinstallfromoneside
! Installedwith“puller”tool
• PopRivet! Poprivetinstalla<on! Usedforno-structuralworkonly! Hollowa,erinstalla<on
BlindRivets• “CherryRivets”
! Notyourhardwarestorerivets
! Widevariety–CherryLock,CherryMax,Huck-Clinch,HuckMax,Olympic-Loc
! CherryMaxAnima<on! CherryMaxcanreplaceasolidrivetofthesamesizediameter• Somemechanicsareconcernedabouttherivetsvibra<ngloose
! InstallCherryMaxRivet
! Hardtoremove• Airframebook(FAA-H-8083-31)page4-49
CherryRivetRemoval
Hi-Shear™
Hi-Shear™
Hi-Shear™
Hi-Lok™• Installa<onVideo• Canbeinstalledwithstandardtools
HuckLockbolt™
HuckLockbolt™
HuckLockbolt™
More grooves for tension version
Rivnut™
Good for thin sheet metal applications
Rivnut™
CherryRivetlessNutplate• Installa<onanima<on
Aircra,ControlCable
Aircra,ControlCable
Aircra,ControlCable
CablePulley
CableFairleads
Aircra,ControlCable• CableMaterial
! CRES
! Galvanizedsteel• Olderstyle
• Typesofcable:! Nonflexible! Flexible! Extraflexible
Aircra,ControlCable
Aircra,ControlCable• CableSize:
! 1/32”through1/2”
! Primarycontrolcablesmustbe1/8”orlarger! Trimtabactuatorcablescanbelessthan1/8”
• Nonflexiblecable! 1X7–7individualwires
! 1X19–19individualwires! Forstraightrunsonly! Can’tpassoverapulley
Aircra,ControlCable• FlexibleCable
! Core• Centersec<on• 7wires• Straight
! Outerstrands• 6strands• Eachstrandhas7wires• Spiraledaroundthecore
! Call7X7• 7strands/corewith7wireseach
Aircra,ControlCable• FlexibleCable
! Usedforenginecontrolsortrimtabcontrols
! Canbeusedwithapulley
• Extra-flexibleCable! 7standswith19wireseach! Cableispreformed
• Willnotspringoutwhencut
! Usedforprimaryflightcontrols
• Cablesareinspectedforbrokenwiresbyrunningaclothalongthecable! Abrokenwirewillsnagthecloth
ControlCableTerminals
ControlCableTerminals
A.AN664Singleshankballend.B. AN663Doubleshankballend.C. AN666Threadedcableterminal.D.AN667Forkendcableterminal.E. AN668Eyeendcableterminal.
Aircra,ControlCable
ControlCableTerminals• Terminalsareswagedon
! Squeezedontothecable
• Swagedconnec<onis100%(full)ofcablestrength
• Cablesaretestwitha“go-no-go”gage! Theterminalmustbe“squeezed”enoughtofitthroughthegage
• Aspotofpaintisappliedtocable/terminalseamtoprovideaninspec<onmark! Ifthepaintisdamaged,thecablehasslipped
• Replacethecable
SwageTools
TerminalGage
A. Gagingaswaged-oncontrolcableterminaltodeterminethatithasbeenproperlyswaged.
B. Typicalterminalgage.
Nicopress
A.Installa<onofNicopress-typesleevesonacontrolcable.B. TypicalNicopressgage.
Nicopress
Nicopress• Cableiswrappedaroundasteelthimble• Acoppersleeveisswagedoverthecable
! Threecrimps• First-center• Second–nexttothimble
• Third–farend! 100%ofcablestrength
• Testedwitha“go-no-go”gauge
Turnbuckles
Turnbuckles• Onesideisthreadedle,andothersideisthreadedright! Turningthebarrelwilleitherlengthenorshortentheturnbuckle
• Nomorethanthreethreadscanbeexposedoneitherendofthebarrel
• Onini<alinstalla<on,theturnbuckleterminalsshouldnotbescrewedinsidetheturnbucklebarrelmorethanfourthreads
• SafetyaccordingtoAC43-13-1B
Turnbuckles
SafetyWire• AC43.13-1B
! Chapter7-Sec<on7• Safetying
! Chapter7–Sec<on10• SafetyMethodsforTurnbuckles
SafetyWire• Usedtosecure:
! Drilledheadboltheadsandscrews
! Valvehandles! Electricaltwist-onconnectors! Oilfilters
! Emergency&oxygenhandles! Turnbuckles
• Whenacastlenutisinstalledonastudthatisscrewedintoacas<ng,itshouldbesafe<edwithsafetywire.
SafetyWire• Materials:
! Usuallystainlesssteel
! Copper/brass–usedforemergency“breakaway”applica<ons
SafetyWire• Methods
! Doubletwist• Nomorethan3fasteners
! Singlewire• Closelyspacedorclosed-geometricalpaPernsuchasatriangle,square,rectangle,orcircle
• Nomorethan24”long
SafetyWire–DoubleTwist
SafetyWire–SingleWire
SafetyWire
SafetyWire
SafetyWire• DoubleTwistSize
! 0.032”diameterwireshouldbeusedonpartsthathaveaholediameterlargerthan.045”
! 0.020“maybeusedonpartshavinganominalholediameterbetween.045and.062”withaspacingbetweenpartsoflessthan2”
• SingleWireSize! Largestsizewirethattheholewillaccommodate
• Followthemanufacturer’srecommenda<ons
SafetyWire
Therecommendednumberoftwistsperinchisdeterminedbythediameterofthesafetywire.
6 to 8 twists per inch is typical
SafetyWire• Safetywiremustbeinstalledinamannerthatwillpreventthetendencyoftheparttoloosen.! Lookslikeinbackwards“S”
• Cleanupsafetywire! Cleanupinstalla<onscraps
! Becarefulwhenremovingwire
• Don’treusewire• Don’tunwireandreinstalls• Don’tknickwire
SafetyWire• Reinstallifindoubt• Alwayscurltheendtopreventexposuretosharpends
• 4to6twistsontheend• Outsidewireshouldgoaroundhead
! Iflimitedspace,outsidewirecangooverthetop
• AC43-13-1Bisthebestreference! FollowtheAC’sinstalla<onexamples
SafetyWire–Method• Twobolt–AC43-1B
! Outsidewire–clockwisearoundfirsthead
! Headonetotwo–twistclockwise! Outerwire–counter-clockwisearoundsecondhead! Twistendcounter-clockwise
! Curlend
SafetyWire• Threebolt–AC43-1B
! Outsidewire–clockwisearoundfirsthead
! Headonetotwo–twistclockwise! Outerwire–counter-clockwisearoundsecondhead! Headtwotothree–twistcounter-clockwise
! Outerwire–counter-clockwisearoundthirdhead! Twistendcounter-clockwise! Curlend
SafetyWire• Threebolt–alternatemethod
! Outsidewire–clockwisearoundfirsthead
! Headonetotwo–twistclockwise! Outerwire–counter-clockwisearoundsecondhead! Headtwotothree–twistcounter-clockwise
! Outerwire–clockwisearoundthirdhead! Twistendclockwise! Curlend
SafetyWire–Turnbuckles
SafetyWire–Turnbuckles• Doublewrapmethodspreferred• Endsmusthaveaminimumof4turns
• FollowthemethodsshowninAC43-13-1BFigure7-26
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