Threading
The square thread that is the industrial standard today is the:
modified
basic
Acme
late common
modified
API is an acronym for:
American Pipe-Industry
Alberta Petroleum Institute
American Petroleum Institute
Alberta Petro-Chemical Industrial
American Petroleum Institute
What are the increments used for each base line when you work in the imperial measurement system mode?
inches
The left/right motion direction for a vertical machining center is the:
X axis
What is the lead of the following thread?
1-8 UNC double start 2A-LH
0.250 inch
Which thread has flank angles of 7 and 45 degrees?
Acme
Buttress
Unified
Whitworth
Buttress
When cutting an API thread on a lathe, the threading tool is set:
perpendicular to the taper
29 degrees to the taper
perpendicular to the machine axis
14 1/2 degrees to the machine axis
perpendicular to the machine axis
What is the least input increment for most machining centers when working in the imperial measurement system?
0.0001 inches
Which positioning style is it when you specify programmed coordinates from the program zero point?
absolute positioning
The up/down motion direction for a vertical machining center is the:
Z axis
What is the lead of the following thread?
1 3/4-4 Acme-2G-LH
0.250 inch
What is the lead of a 3/8-16 UNC double start thread?
0.125 inches
The fore/aft motion direction for a vertical machining center is the:
Y axis
The origin of the rectangular coordinate system as it is used with a CNC machining center is called the:
program zero point
What is the pitch of a 3/8-16 UNC double start thread?
0.0625 inches
What are a worm thread and worm wheel used for?
to transmit motion and reduce speed
What taper does an NPT thread have?
0.750 inch per foot or 1 degree 47 minutes
The machine origin position from which all program zero assignment values are taken is called:
the programmed point of the cutting tool
the program zero point
the work shift value
the zero return position
a consistent Z surface on workholding device
the zero return position
When are you required to include a polarity sign in a coordinate value?
When the value is negative.
Program zero assignment values are the:
lengths of each tool used in the program
distances from the zero return position to the program zero point in each axis
length, width and height of the workpiece
distances from the program zero point to the spindle nose
distances from the zero return position to the program zero point in each axis
When are multiple start threads used?
when you want to increase the lead of a thread without having to use a deeper, coarser pitch
How is clearance provided on basic general purpose and stub ACME threads?
the major and minor diameters are altered
If the program zero is in the lower left hand corner of a workpiece, what polarity do all of the X and Y coordinates within the workpiece have?
positive
In order to specify motion commands in a CNC program, you must be able to specify positions through which you want cutting tools to move. What system do you specify these coordinates in?
the rectangular coordinate system
Name 3 translational thread forms.
-Acme
-Square
-Buttress