hand tools measuring devices - gavilan collegehhh.gavilan.edu/.../handtoolsmeasuringdevices.pdf ·...
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Screwdriver
The tip of a slot screwdriver should be ground so its sides are parallel, and it should fill approximately 75% of the width of the slot in the screw.
Hacksaw• Usearidgeorfixedframe• Teethalwaysfaceforward
v Cutsontheforwardstroke
• Releasebladetensionwhendone• Startcutwithrearwardstrokesonly• Liftsawonrearwardstokes• Selectthecorrecttoothcountformaterial
Files• Alwaysuseahandleonthetang• Liftorremovepressureonthereturnstroke• Cleanwithafilecard
v Keepsteelandaluminumfromcrosscontaminating
• Keepdry• Don’tstack• Siliconspraycanhelpkeepthingsfromsticking
v Notoil
DrillBits
Tip angle for metal is usually 118° Clear plastics require a special tip design Sizes available in fraction of an inch, metric and numbered Soft metals – high speed and light pressure Hard metals – low speed and higher pressure The flute forms the cutting edges of the point
TapandDie• Threads
v UNF–finev UNC–coursev NationalTaperPipe(NTP)
• Taperedtosealfluidsv Rolledandcut
• Rolledisstronger
• Usematchingdrillsize• Usecuttingoiland/orgrease(catchshavings)• 1/2turnforwardandthenbackup• Straightandslow
Micrometer• Verniermicrometermeasuresin1/10,000”or0.0001”Page9-24–Fig9-390.2947shouldbe0.2957
• Agaugeblockisusedtocalibrateamicrometer• Remembertoaddtheframesizetothemeasurementfromthesleeve/thimble
• Useratchetstoptotightencaliper• Keepataconsistenttemperature• Introvideo• Readingamicrometer• Demonstratepoppetvalvestemandpistonpinoutofroundmeasurements
FeelerorThicknessGageMeasures: 1. Piston ring gap 2. Ring and lands 3. Connecting rod twist 4. Flat Surface
Video