Drilling Flashcards
what is drilling
creates a hole in the material
whats the difference between drilling and boring
drilling creates, boring enlarges
what are the 2 difderent types of holes/definitions
through hole- exits the oppisite side
blind holes-doesnt exit the oppisite side
difficulties in drilling
difficult to cut hole on size
poor finish inside the hole
drills want to walk arcross material
can leave big burrs
as hole get deeper harder to keep centred
what is special about a upright drill press
belt drive
had high speed and low torque
what is special about a gear head drill press
more powerful
slower speed for bigger drills
powerful quill feed
what is a radial arm drill
designed for large holes
has and arm that canmove up/down/rotate about colum
head can move in and out along with the arm
parts are mounted to base
what are the 3 ways a drill press can hold a part/discriptions
vice-holds part between opisite jaws
fixture-customed designed for particular work peice
drill jig- similar to fixture but also guides the tool along
what is reaming
enlargning holes with a better accuracy and finish of the walls
a finishing operation
what is the purpose of reaming
slightly enlarge the hole
proides better tolerance
improve surface finish
what are 5 different types of reamers
hand reamers
machine reamers
morse taper reamer
tapered reamer
expandable reamer
what is tapping
cutting or forming a thread
only allowed to exsisting hole
what are the 3 main tap styles
straight flute
spiral point tap
spiral flute tap
what is a straight flute for
mainly for hand tapping, can e used for machine tapping
what is a sprial point tap for
pushes chip ahead of tap
good for through holes
what is a spiral flute tap for
good for deep blind holes
draws chips out of the hole
what is a tap lead in
end of standard tap is chamfered
helps align the tap to the hole
what are the 3 types of taps/ how many ttapered threads
plug tap-3-5 threads
taper tap- 7-10 threads
bottom tap- 1-2 threads
what is the purpose of the 3 types of taps
taper tap- used for threading through material ,first threads in a blind hole
plug tap- used for near the bottom of a blind hole
bottom tap- used for threading the bottom of a blind hole
what are form taps
no chips produced
deforms peice instead of cutting it
doesnt work on all materials
yight tolerance on the drillled hole
what are threading dies
can be used to vreate external threads on a rod
suited for reparing and cleaning up threads then creating them
what is centre drill
used for drilling a hole between centres
what is spot drilling
used for precise hole placement
creates a shallow pilot hole
what is counterboring/what is it used for
provides a steep hole
used when the gead of faster has to be flush
what is counterinking
a conical hole is created
what is spot facing
a shallow couter bore
used to create flat landing surface
