Mid-Term Flashcards
When is it safe to leave operating machinery unattended?
Never
What is the hazard of rags around moving machinery?
They can pull you in.
What state must a machine be in before repairing?
Zero-Energy State.
Storage drums must be grounded to avoid which hazards?
Static spark and combustion.
A safe pressure for shop airlines is?
30 psi.
What shape is a class A fire extinguisher symbol?
Triangle.
What shape is a class B fire extinguisher symbol?
Square.
What shape is a class C fire extinguisher symbol?
Circle.
What shape is a class D fire extinguisher symbol?
Star.
Proper lifting requires?
A straight back and leg muscles.
A Class A fire could be?
Paper or wood combustibles.
A Class B fire could be?
Chemicals/solvents ie. Varsol, grease.
A Class C fire could be?
Electrical components.
A Class D fire could be?
Metals ie. Magnesium, lithium, etc.
What is the typical function of V blocks?
Hold round, square or octagonal stock.
Which angles are quickly compared with the square head of a combination set?
45 or 90 degrees.
The centre head of a combination set has which included angle?
90 degrees.
What is the function of a protractor head in a combination set?
To compare or layout semi-precise angles.
Which liquid is used to contrast steel for scribing lines?
Layout blue.
What is the function of dividers?
Bisect any angles, scribe arcs and circles, compare layout points.
What is the function of trammels attached to a beam?
Layout large arcs and circles.
Which method is used to check squares of large layout pieces?
-
Why are surface plates used with care?
They maintain a level of accuracy for the shop work.
Which is the best material for surface plates?
Granite.
What is the purpose of prick punching before machining?
Layout lines are often removed with machining.
How is cross filing done?
Using a double cut file for fast removal of material by cross cutting.
What is the function of a file card?
To clean a file.
Why don’t you use a scale for deburring?
It reduces the accuracy of the scale.
How is a micrometer calibrated?
Measure a known distance and adjust the nut using a C Wrench.
What is the smallest bore size an inside micrometer can measure?
1.500”
One rotation of a metric micrometer thimble advances it how much?
0.50 mm
How is a depth micrometer read?
Graduations are reversed from an outside micrometer.
What two levels of accuracy can be obtained with a metric vernier micrometer?
0.05 mm - 0.02 mm
What level of accuracy can be obtained with a Standard (non-vernier) micrometer?
0.001” (One Thousandth)
How many graduations on either side of zero on a bevel protractor?
12
How many graduations on the thimble of a metric micrometer?
50
How would you compare outside dimensions?
Outside calipers.
Layout of angles with a Sine bar and gauge blocks is?
The most accurate method.
Which tool is used to measure small diameter holes?
Hole gauges.
Calipers and dividers (protractors) are which type of tool?
Comparison.
Which tool is used to quickly check accuracy of specific parts?
Fixed gauges (Go/No-go).
What is the smallest graduation on a 6” scale?
1/64th of an inch.
How is imperial tap drill size calculated?
TDS = D -1/N
Major Diameter minus 1/ Number of threads per inch
What hand tool is designated second cut?
Machinist file.
For safety a cold chisel head should be ground to prevent?
Mushroom head that creates shrapnel.
Tap drill size for M8 x 1.25 is?
6.75mm
TDS= M - P
* Major Diameter minus Pitch
What is the ideal tip angle of a flat chisel for steel?
70 degrees. *Less for softer material.
In which stroke is moderate pressure applied when filing?
Forward.
What material are soft face hammers made of?
-
How many teeth of a hacksaw should be in contact at all times?
Minimum of 2, Maximum of 24.
Which hand tap is best suited to start a hole?
Taper.
Which hand tap is best suited to finish a blind hole?
Bottoming.
Which taps are used to cut threads in hard material?
Serial.
What material are the hard jaws of a bench vise made of?
Cast steel.
The temperature of the workpiece of will affect?
Accurate measurement.
Draw filing gives a good finish and can be very accurate if using?
Single cut file, held 90 degrees to the direction of the work.
