Sheet Metal Fabrication Is Avery Broad Subject Area and Uses

IntroductiontoSheetMetalFabrication

Description

Sheet metal fabrication is avery broad subject area and uses manytools,machinesandjoiningprocesses. Sheet metal workers fabricate, assemble,alter and installavarietyof sheetmetalproducts. Typicaljobs performedby a sheet metal workerincludeHVAC(Heating, VentilationandAirConditioning) ductwork, industrial sheet metalwork andresidential sheet metal work

as well as aviation construction. Sheetmetalsmithsalso workon stainless steel hospitalandkitchenequipment,industrialexhaustsystemsandroofingandflashing(copper,aluminum,stainless steel and galvanizediron).

This Activity Planis designed tointroduce students to thevarious types of sheetmetalas well as common introductory fabricationprocesses,suchasmeasurement,layout, rivetingand folding. More experienced studentswill alsobe introduced tomore advanced options like

brazing.The Activity Planisflexibleandallowsfor modification tosuitindividualstudentneeds.

LessonObjectives

The student willbeableto:

•Brieflydescribe whatisgenerallymeantbytheterm sheetmetal

•Correctlyidentifycommonsheet metal types and describetheircharacteristics andproperties

•Namebasicfabrication equipmentand list someoftheoperationsdonewith them

•Completebasicfabricationprocesses usingcommonsheetmetaltoolsand equipment

Assumptions

Theteacher will:

•Be a certifiedtechnologyeducation/industrialeducationteacher

•Befamiliar with themetal shopthatthis activity planisbeingproduced in

•Haveexperience withall aspectsof the given metal shop,includingmachines,toolsandprocesses

The student will:

•Havean understandingofmetallurgy, shapesandforms of metals

•Understandbasicprinciples and methods oflayout

•Beattentive andparticipatory

•Recognizethat appropriateattitudesarethebest insurance for safety

•Safely work inthe metal shop

Terminology

Aluminum:ametallicelementthatisusedasanalloyingagentforagroupof alloys.

Aviationsnips:ahandtooldesignedtocutsheetmetalintointricatedesigns.Canbeusedtocutcompoundcurves.Red=leftcutting;Green=rightcutting;Yellow=universal,abletocutinanydirection.

Barfolder:asheetmetalmachinethatisusedtocreatestraightbendsinsheetmetal.

Beadroller:ahandrollerdesignedtoaddraised,curveddecorativehemstosheetmetal.

Beverlyshear:asmallhand-operatedpieceofequipment thathastwobladesthatwhenpassedagainsteachothershearthemetal.

Boxandpanbrake:asheetmetalmachinethatisusedtocreatebends,hemsandboxes insheetmetal.

Brass:an alloy metalconsistingofamixtureofcopperandzinc.Gold/yellowin colour.

Brazing:aprocessinwhichtwometalsarejoinedusinganon-ferrousfillerrodthatismeltedattemperaturesover450°C(840°F).

Centrepunch:ataperedpieceofmetalthatisusedtocreateanindentinmetaltocentrethedrillbitwhiledrilling.

Coldrolledsteel:steel thathasbeenrolledinto itsfinishedshapeafterithasbeencooled.Afterthisprocessiscompleteitisputthroughapicklingsolutionor dilute acidtoremove theironoxidecoating.

Combinationroller:amachineusedtoperformburring,crimping,wireedgingandotherformingtechniquesonsheetmetal.

Copper:ametallicelement,orangein colour.Commonlyusedinartmetal,electricalworkandasanalloyingagent.

Emerycloth:anabrasiveclothusedtoremovematerialandsmoothsurfaces.

Englishwheel:ahand-operatedtoolthatenablestheformationofcompoundcurvesfromflatsheetsofmetal.

Expandedsheetmetal:sheetsmadebycuttingslitsintoregularmetalsheetsandstretchingthemouttocreatenumerousopeningsinadiamondpattern.Expandedsheetsarelighter,strongerandless expensive thanregularflatsheets. They alsoallowforthefreepassingofliquids,lightand sound.

Ferrous:ametalcontaininghighlevelsofiron.

File:ahandtooldesignedtoshapeandsmoothmetal.Available inavarietyofshapesandsizestofitdifferentprojects.Madeofhardenedsteelwithvaryingtexturesto remove largeorveryminimalamountsofmaterial.

Galvanizedsteel:asteelsheetthatisdippedinazinccoatingtoprotectit.

Gauge:thethicknessofthesheetmetalmeasuredwithathicknessgauge.

Hammer:atooldesignedtogive aheavyblowtoanobject.Madewithavarietyofdifferentheadmaterialsforspecificpurposes.

Hem:abordermade by foldingover theedgeofapieceofsheetmetaltoincreasestrength,preventexposure ofasharpedgeandincreasetheproduct’s durability.

Hotrolledsteel: steelthatisformedinto itsfinishedshapewhileredhot.Itisidentified by itsblackoxidecoatingthatisformedduringtherollingprocess.

Letterandnumberstamps:hardenedsteelbarswithlettersandnumbers.Usedtopermanentlylabelmetalprojects.

Non-ferrous:metalsthatcontainlittletonoiron.

Oxyacetylenewelding:weldingtorchesthatuseacombinationofoxygenandacetylenetoproduceaflamehotenoughtojoinmetaltogetherusingafillermetal.

Rivet:anon-threaded fastenerusedtojoinmetalpiecestogetherthatdonotneedtocomeapart.

RoperWhitneypunch:ahandtoolusedtopunchholesinsheetmetalstock.

Ruler:aprecision measurementtoolthatisalengthofsteel withmarksatregularintervals.Scribe:along,pointedpieceofhardened steelthatisusedtomark layoutlinesonmetal.Sheetmetal:atermusedtodescribeavarietyofthinrolledmetalsheetstock.

Sliproller:hand-drivenequipmentthatcontainsthreehardenedsteelrollers:adrive roller,agrippingrollerandaradiusroller.

Spotwelder:aresistanceweldingtechnique.

Squaringfootshear:afoot-controlledmachineusedtocutsheetmetalstock.

Stainlesssteel:analloyed steeldesignedtohave greatlyincreasedcorrosionresistancecomparedtocarbon/alloy steel. Commonalloyingingredientsincludechromium(usuallyatleast11%),nickel andmolybdenum.

Tinsnips:ahandtooldesignedtocutout layoutsonsheetmetal.Alsocalledhandshears.

Welding:theprocessbywhichtwoormoremetalsarejoinedtogether byheatingthemetalstothepointwhere theyfusetogether.

EstimatedTime

1–2 hours

RecommendedNumberofStudents

20, basedontheBCTechnology EducationAssociationBest PracticesGuide

Facilities

Metalshopfacilitywithall necessary tools,materials and equipment

ToolsandEquipment

Personalprotectiveequipment

Hand Tools

•Aviationsnips

•Centre punch

•Emerycloth

•Coarseandsmoothfiles

•Gauge

•Peening hammer

•Letter/number stamps

•Rivetsrivet gun

•RoperWhitney punch

•Ruler

•Scribe

•Tinsnips

StationaryEquipment

•Barfolder

•Beadroller

•Beverley shear

•Box andpan brake

•Combination roller

•English wheel

•Oxyacetylenewelder

•Sliproller

•Spot welder

•Squaringfootshear

Materials

Multiple samplesof the varioussheet metalsyou plan to introduceduring thecourse foridentificationanddemonstrationpurposes.Thismayincludealuminum,copper,brass,galvanizedsheetmetal, cold rolledsteel,aluminumandhotrolledsteel.Itissuggestedthatteachers demonstrate theproceduresusingmaterialsthatwillbe foundin their individual shopaswellasequipmentthatis specific totheirshop.

Resources

Boxandpanbrake

RoperWhitneypunch

Beverlyshear E6F39C76DEA3A5DAEE2EE6F39C76DEA3A5DA&rvsmid=074FB5E6FA3B3931B7F7074FB5E 6FA3B3931B7F7&fsscr=0&FORM=VDMCNR

Barfolder

Englishwheel

“HEADSUP!forSafety”handbook

BCTechnologyEducationAssociationBestPracticesGuide

Teacher-ledActivity1:IntroductiontoSheetMetal

1.Beginby gatheringall tools, materials andequipment.

2.Introduceeachtypeofsheetmetalandgive a briefdescriptionofeachindividual type,common usesandidentifyingcharacteristics.(SeeMaterialIdentificationStockIdentification Activity Plansformoredetailedinformation.)

3.Distributethe attached sheetmetalidentification/descriptioninformationsheet.

4.Demonstratehowto check thickness ofsheetmetalstockusingthe thickness gauge.

5.Providesamplepieces for studentstohandle and becomefamiliarwith.

StudentActivity

1.Set upstationswithsample pieces of sheetmetal.

2.Have studentsidentify anddescribe each sample,usingthe attached sheet metalidentificationworksheet.

3.Providemagnets for students to test formagnetic properties of thesamples.

4.Students willalso needathickness gauge tocorrectly test formaterialgauges.

Teacher-ledActivity2:

IntroductiontoFabricationProcesses

1.Set up aworkstation with allhand tools commonly used inthe metal shop.

2.Work througheach handtool, describing its name, use and anyother specialty instructions.(SeeIntroductiontoToolsandEquipment Activity PlanandsubsequentPowerPointpresentationsfor more detailed information.)

3.Oncehandtoolsare complete,move the studentgrouptoeach of the stationarypiecesof equipmentlocatedin themetal shop. Ateachdescribe thetool nameand use anddemonstrate safeworking practices.

4.Whenalltools and equipmenthavebeen appropriately andsafelydemonstrated, studentscanbeginthe individualhands-onportionofthe activity.

StudentActivity

1.Set up workstations thatincludeone or twoofthehand tools commonly used inthe metalshop(e.g.,RoperWhitney punch along with rivets and arivetgun).

2.Have studentswork througheach station, completing thetaskof using the equipment onasample pieceofsheet metal.

3.Workstations shouldalso includethe stationaryequipmentsuchassquaringfoot shear,boxandpan breakand spot welder.

4.Once studentshave completedeach activitytheyshould haveavarietyof sample pieces ofsheet metal that have been cut, formedor joinedin someway.

5.Theattached studentstationworksheet will act as aguideto ensure studentswork througheachstation. Moreexperienced studentsor peertutors could beused to signoff oneachstudent as they completeastation.

Additionalstations could includecombinationroller,English wheel, bead roller or brazing.Theseadditional stations mayrequirelargersample pieces ofmaterialto ensure safe workingpractices.

Note: Bothactivity worksheets are generalin nature andare designedto providea guidefor thestudent activities. They canbe addedtoor subtracted from to suitindividualteacher and shopclassroom environments.

Assessment

Consider co-creating theevaluationcriteriawithyourstudentsatthebeginningoftheactivity/project. You maywanttoincludethe following:

•Safeworking procedures atall times

•Personalandproject management: gooduseof time, attitude, effort

•Accurate measurements andlayout

•Appropriateuseof tools

•Allburrs andsharp edgesaresmooth

•Instructionswerefollowedthroughoutthe activity

•Correct identificationofmaterials

•Descriptionofmaterialsiscompleteandincludescharacteristicsand properties

Sheet Metal Identification Worksheet

Name

Date

Samplenumber / Nameofsample / Gauge/thickness / Ferrousyes/no / Conductivity / Describethesample(colour,texture,etc.)
#1
#2
#3
#4
#5
#6
#7

SheetMetalFabricationIntroductionActivity

Name

Date

Material: 6"×6"sheet metal

Station1: Usingthematerialsandequipment provided,measure,lay outandscribelinesthatdivideyourmetal intonine2"×2" evensquares.

Station2: Squaringfootshear:Cutyourmaterialintothreelongstrips.Theyshouldbe2"wide×6"long.

Station 3: Tinsnipsandfiles:Usingthesnips,cuttwoofyour longstrips intosix2"squares.Usingthefiles,filealledgesoneachsquareto remove allburrsandsharpedges.

Station4: Beverly shear:Cutyourlastlongstripinto onepiecethatis2"×2"andasecondpiecethatmeasures2"×4".

Station5: Letter/number stampsandhammer:Oneachsquarestamp your initialsandanumberfrom1through8.

Station6: Centrepunch,RoperWhitneypunchand riveting:Centrepunchtwoholesoneachoftwoofyour samples,foratotaloffourholes.ThenusetheRoperWhitneytopunchoutallfourholes.Oncethatiscomplete,usetherivetsandrivetingguntojoinyoursamplepiecestogether,aligningalltheholes.

Station7: Spotwelder:BesuretouseALLsafetygear.Selecttwodifferentsamplesofmaterialandjointhemtogetherusingthespotwelder.Be creative.

Station8: Barfolderor boxandpanbrake:Foldthe2"×4"samplepiecetoa90°angleonthescribed line. YourfinishedproductshouldbeanLshape.

Station9: Aviationsnipsandfiles:Usethesnipstocut,roundorcreateslightlycurvedcornersononeof your samplepieces.Smooth any burrsorsharpedgesonthecornersusingthefile.

Station10:Emeryclothandpeeninghammer:Usethehammertotextureoneofyour samplestocreateadimpledpattern.Usetheemeryclothtoaddpatternsandtextureaswellassmooththesurface.

Station11:Barfolder:Foldasinglehemononeofthesamplepiecesyou havenotpreviouslyworkedon.

Station12:RoperWhitneypunch: Punchaholeinonecornerofeachof yoursamples.Join yoursamplestogetherusingthestring/wire/keyringprovidedandhandinto your teacher.Makesure you havecompletedallstationtasks.

Sheet Metal Identification:CharacteristicsandProperties

Sheetmetalname / Characteristicsandproperties / Sampleimage
Aluminum / Acold-rollednon-ferrous material over
0.2 mm thick butnotexceeding 6 mm.
A silver-coloured, low-densitymetal witha huge variety of commercialapplications. Unalloyed aluminum isductile, exhibits moderatestrengthandisvery resistant to corrosion under mostcircumstances.
Aluminum canbedramaticallystrengthened bytheaddition ofappropriatealloyingelements(Cu,Mg,Mn, Si, etc.) and subsequentheat/worktreatments. Thelowdensity of aluminummakes it aperfect materialfor aerospaceand in other transportation fields.
Brass / Brassis an alloy of copper andzinc.Brass has lowfrictionproperties andacousticproperties.
Applicationsincludedecorativeand architectural uses, condenser/
heat exchangers, plumbing, musicalinstruments,andfasteners.Non-ferrous.
Coldrolledsteel / Rollingsteelatambient temperature (orbelowitsrecrystallization temperature)increasesits strengthand hardnessanddecreases its ductility.In addition toimprovement of mechanicalproperties,coldrolling results inmorecontroloverthe shape and dimensions of the finishedproduct.
Coldrolled steel has an improvedsurfacefinish, which makes it common inthecreationoffurniture, appliancesandotherconsumergoods. Ferrous.
Sheetmetalname / Characteristicsandproperties / Sampleimage
Copper / Excellent corrosionresistanceand highthermalconductivity.Applicationsincludearchitecturaluses,coinage,condenser/heat exchangers, plumbing,radiator cores,musicalinstruments,locks,fasteners, hinges. Non-ferrous.
Smallamounts ofalloyingelements areoftenadded tocopper toimprove certaincharacteristics.
Expandedsheetmetal / Sheets aremade by cuttingslits intoregularmetalsheets andstretching themout to create numerous openings inadiamondpattern.
Expandedsheets are lighter,strongerand less expensive than regular flatsheets. They alsoallowforthefreepassingofliquids, lightandsound.
Ferrous. /
Galvanizedsteel / Hot-dipgalvanizing is theprocess ofcoatingironor steelwithathinzinclayer,by passingthe steelthroughamoltenbathofzinc at atemperature ofaround460°C (860°F). When exposedtotheatmosphere,purezinc reactswithoxygen toformzincoxide, which
furtherreactswithcarbondioxide toformzinc carbonate, a dull grey, fairly strongmaterialthat stopsfurthercorrosioninmany circumstances,protectingthesteelbelow fromthe elements.
Galvanizedsteel iswidely usedinapplicationswhererustresistanceisneeded, and can be identified by thecrystallizationpatterningonthesurface(oftencalledaspangle).
Ferrous.
Technically,galvanizedsteelcanbewelded,butextremecautionis
needed,astheresultingzincfumes arelethalifinhaled.
Sheetmetalname / Characteristicsandproperties / Sampleimage
Hotrolledsteel / Hotrolling involves theproductionofsheet metalfrom billetsbypassingthesteelthroughrollers whileabove itsrecrystallization temperature (over 926°C
/ 1700°F). Multiple passes through therollersmay benecessaryto producethefinal desired dimensions. It is identifiedbytheblack oxide coatingthatis formedduringtherolling process. Ferrous
Stainlesssteel / Analloyed steeldesigned to havegreatly increasedcorrosionresistance
compared to carbon/alloy steel. Commonalloying ingredients include chromium(usually atleast11%),nickel andmolybdenum.Ferrous.