drilling Flashcards
what are sensitive drill presses used for
small, precise work (hole up to 1/2)
What drives a spindle on a sensitive drill press
V-belt
5 types of drilling machines
Sensitive drill press
Upright drill press
Hand drills
Magnetic base drill
Radial drilling machine
What is an upright drill press used for
Larger holes (1/2 to 4 inch)
What is a magnetic base drill
Heavy portable drill and secures to the workpiece by electro magic base
What is a radial drilling machine used for
Drill holes in very large workpieces
What would your rpm be if your diameter is 2” and you have 50 sfpm
100 rpm
What would your rpm be if your diameter is 2” and you have 50 sfpm
100 rpm
Two methods of manual feed on a radial arm drill press
Hand feed lever
Hand wheel
Two ways of sizing a sensitive or upright drill press
The distance from the centre of the spindle to the column
Largest diameter of workpiece that can be centred under the spindle
Radial arm drilling machines typically range in size from
3 to 14ft with a column diameter of 30 inches and more
Drill chucks are sized according to what
Largest drill they can hold
shank of drills when they are larger then 1/2 inch have what
Tapered
Morse tapers are separated how
With a drift
What do you use when sequence of operations must be done repeatedly
Quick change tool holder
What does a drill jig (holding device) do
Locates a hole accurately on a workpiece
What are the 3 parts to a twist drill
Point
Body
Shank
Two types of shanks
Straight
Taper
You have a drill diameter of 0.75” and a sfpm of 120, what is the rpm
640 rpm
Straight shank are used on drills up to
1/2 inch diameter
Taper shanks have a standard taper of what
5/8 inch per foot
What has two helical flutes
Twist drill
What is the margin
Narrow raised section that runs along the flutes for their entire length
The geometry of a point on a drill bit are defined by what
Cutting lips
Chisel edge
Lip clearance
9 specialty drills
High helix drill
Core drills
Oil hole drills
Straight fluted drills
Twist drills
Step drills
Saw type hole cutter(hole saw)
Masonry drill
Centre drill
Centre punch mark should be at least what size
As large as the chisel edge of the drill bit
What is the most common drill bit angle
118 degrees
150 degree drill bit angle is meant for cutting what
Hard materials
90 degree drill bit angle is meant for cutting what
Soft materials
What bigger the drill bit the more what
Feed pressure needed
3 methods used for hole location transfer
Twist drill method
Transfer punch method
Transfer screw method
Most common countersink angle
82 degrees (most screws have an included angle of 82 degrees)
What is counterboring
Enlarging the top of an existing hole
What size is the pilot guide for the counterbore
0.002 and 0.005 of an inch smaller than the hole diameter
How is cutting speed measured
Metres per minute (m/min) or
Sfpm
What is the fastest moving part of a rotating part such as a drill bit
Outside edge also often called peripheral speed
Four major parts of a drill press
Head
Column
Table
Base
