Intro to CNC Flashcards
Learn the basics
Why do we measure?
To control what we produce
What is the standard temperature for measuring?
68 degrees F or 20 degrees C
Define “Dimensions”
Desired size of part feature
Define “Limits”
Maximum and Minimum dimension tolerated
Define “Tolerance”
Distance between limits
How many Millimeters in an inch?
25.4
How many teeth of a saw must be touching the part at all times?
3
What is the ratio for the RPM for a Reamer in relation to the RPM for a drill of the same size?
0.5
At what point should you polish a workpiece on the lathe?
Under no circumstances
How are the feed rate on a lathe given as?
Thousandths per Revolution
What is the name given to the width of a cut produced by a saw blade?
Kerf
What is the included angle on the most commonly used countersink used for flat head machine screws in the USA?
82 degrees
What is the drill point angle of a general purpose drill bit?
118 degrees
Which type of gage is used with a surface plate to measure and mark off horizontal lines in precision layout work?
Height gage
What is the name given to a transfer tool which can be used with an outside micrometer to measure a hole diameter?
Telescoping gage
What process increases the diameter of a hole to a certain depth in order to allow a screw head or nut to be positioned flush with or below the workpiece surface?
Counterboring
What process cuts a tapered opening in a hole so that a flathead screw can be installed flush with the workpiece surface?
Countersinking
What is the name of the guide on the end of a counterbore that keeps it aligned in the existing hole?
Pilot
What is the name of a hole that is only drilled partially through a workpiece?
Blind Holes
What is the name of the V-shaped rails on the top of the lathe bed?
Ways
Which part of the lathe is determined by the biggest diameter workpiece that can be mounted in the spindle without touching the ways?
Swing
What kind of chucks have jaws that advance and retract simultaneously?
Universal
What is the process of using a single-point cutting tool to enlarge an existing hole?
Boring
Define “Crest”
The top of a Thread
Define “Flank”
The sides of a Thread
What are the advantages of a Ball Screw Thread?
Very little friction
What is “Tapping”?
Creating internal threads
Define the “Shank”
The part of a Drill Bit that attaches to the mount
What makes a Taper Shank unique?
Its conical shape
Define “Reaming”
Finishing a drilled hole
The Drilling speed is (3.86 times X) divided by the diameter of the workpiece. What is X for Aluminum?
300
The Drilling speed is (3.86 times X) divided by the diameter of the workpiece. What is X for Mild Steel?
100
The Drilling speed is (3.86 times X) divided by the diameter of the workpiece. What is X for Brass?
200
What is the ratio for Counterboring RPM compared to a drill of the same size?
2/3
What is the ratio for Counterboring RPM compared to a drill of the same size?
1/2
The Drilling speed is (3.86 times X) divided by the diameter of the workpiece. What is X for Bronze?
200
The Drilling speed is (3.86 times X) divided by the diameter of the workpiece. What is X for Tool Steel?
50
The Drilling speed is (3.86 times X) divided by the diameter of the workpiece. What is X for Cast Iron?
75
What makes Climb Milling different from Conventional Milling?
The Cutter rotates in the opposite direction of the Table Feed in Climb Milling
How much of a Mill Cutter should be in contact with a workpiece at maximum?
1/8 of an inch
