Studied by 76 Peopleaccuracy
Tags & Description
accuracy
The degree to which the measured value agrees with the true value or against the standard. Instrument must be maintained by proper and regular calibration.
boring
Enlarging a hole with a SINGLE POINT CUTTING TOOL.
What lead angle do chamfer tools have?
45 degrees
chips
Material removed from a part in all machine processes.
chip load
Cross sectional thickness of a tooth that shears off with a cutter.
clearance angle
AKA relief angle. Angle of a cutting tool. Primary clearance angle prevents the cutting tool from rubbing against a workpiece. Secondary clearance angle must be large enough to clear a workpiece and allow chips to escape.
climb
A direction in milling. We prefer climb milling over conventional milling, as climb milling creates thick-to-thin chips that minimize tool overheating. Pictured is climb milling.
collet chuck
Used to secure parts. Acts as a collar around an object being held. Not to be confused with a three jaw chuck.
compound slide
The slide of a lathe that goes "diagonally." Reads in diameter.
cross slide
The slide of the lathe that goes "in" to set the depth of cut. Reads in diameter.
cutting fluids
Cool & lubricate.
materials for cutting tools
carbide, high speed steel, carbon steel. carbide is faster than high speed steel is faster than carbon steel. remember BIDEN HAS CAR (carBIDE, HS steel, CARbon steel)
depth of cut
How deep you go in a cut.
die
Used for threading in thread callouts for A (used for doing external threads). KNOW DIFFERENCE FROM TAPPING
drilling
Machining process that makes a hole
edge finder
Finds the edge of a part
end mill
Peripheral milling of a part, does work parallel to a surface of a part.
face milling
Face milling of a part, does work normal (perpendicular) to a surface of a part.
facing
On a lathe, cutting off the front of a part. Know the difference between facing and turning.
reaming
Fixed to an exact size with reamer, this process creates a hole to a tight tolerance, good for press fitting.
head stock
On a lathe, where we adjust stuff.
units for mill table feed
in/min
units for lathe feed rate
in/rev
lead angle
The angle between a cutting edge of a tool and the workpiece.
machine tools
All machining is done on machine tools.
milling
Stationary multi tooth rotating tool, you feed your part past it.
nose radius
Strengthens cutting tool, improves finish & impacts tool life.
precision
Also known as repeatability. Precision is the degree to which the instrument provides repeated measurements of the same standard.
Peripheral milling
Does work parallel to a surface of a part.
primary industry
Cultivate & exploit natural resources
secondary industry
Converts primary industry outputs into products.
tertiary industry
Service sector of economy.
primary datum
Surface of a part, it is a plane. 3 degrees of freedom constrained.
secondary datum
Line that the part is positioned against. 5 degrees of freedom constrained.
tertiary datum
Part is positioned against this point. 6 degrees of freedom constrained.
rake angles
The angle at which a cutting tool meets with a rake surface when cutting a part.
relief angle
AKA Clearance angle. Angle of a cutting tool. Primary clearance angle prevents the cutting tool from rubbing against a workpiece. Secondary clearance angle must be large enough to clear a workpiece and allow chips to escape.
rule of 10
Measuring device must be 10x more precise than specified tolerance.
right hand rule
For identifying axis of CNC coordinate system. See image attached.
RPM
revolutions per minute
sawing
A machining process using blades as a cutting tool.
shear
The act of removing chips from a part. Exposes cutting tools to stress and high temperatures.
spindle
Something that rotates on a machine
surface speed
velocity between tool & workpiece, when the surface speed is too high, the tool gets too hot
tailstock
part of lathe used for drilling, etc.
tap
Used for threading in thread callouts in B (internal threads).
thread class
number 1,2, or 3 that identifies the tightness of thread. 1 is loose, 2 is medium, 3 is tight.
thread size
size of a thread. appears first in a thread callout.
thread pitch
thread pitch = 1/TPI where TPI is threads per inch.
threads per inch
appears after thread size in thread callout.
three jaw chuck
used for holding workpieces or tools, has 3 "jaws" that get tightened to hold things in place
turning
On a lathe, cutting off the sides of a part. Know the difference from facing.
twist drill
another way to say drill
vise
part of the mill that holds parts in place
work coordinate system
origin or "0 point" for program or part
width of cut
how wide of a cut you make in a part
spot drill/center drill
creates conical hole for drill bit to drill in the right location
4 ways to specify drill size
fractional, metric, number, letter
MMC
most material condition, for shafts it is the largest number, for holes it is the smallest number
LMC
least material condition, for shafts it is the smallest number, for holes it is the largest number
if a part has negative allowance and negative clearance, what kind of fit does it have?
interference fit
if a part has negative allowance and positive clearance, what kind of fit does it have?
transition fit
if a part has positive allowance and positive clearance, what kind of fit does it have?
clearance fit
UNC
unified national coarse
UNF
unified national fine
thread angle
60 degrees
thread engagement
75%
UNEF
unified national extra fine
depth of thread
at end of thread callout, gives thread depth for good internal threads, DIFFERENT FROM TAP DRILL DEPTH
tap drill depth
distance from top to very bottom of tapped area
nodes
where we want a feature to be located
runout
how well something rotates around a central axis
feature control frame
for specifying gd&t
contour rule
when dimensioning, always dimension where the contour shows the most (the part that sticks out/is easy to measure with a caliper)
cold saw
circular saw creates precise, burr-free cuts w/ no sparks or generating heat
RPM calculation
N=4V/d
feed rate calculation
F = N x ft x t
broaching
makes holes not round. does not create holes, changes shape of holes. for example, hexagonal shapes.
