M7.6 Flashcards
If a hole needs to be reamed, what should the initial hole size be?
A. Larger than the reamed hole size
B. Smaller to allow for material removal
C. The same size as the final hole
B. Smaller to allow for material removal
In the number and letter drill size system, which letter represents the largest drill diameter?
A. A
B. Z
C. G
B. Z
In the number drill size system, what is the smallest size represented in the 1-80 range?
A. 1
B. 80
C. 40
B. 80
Which of the following are the three basic classes of fit in engineering?
A. Clearance Fits, Interference Fits, Transition Fits
B. Compression Fit, Clearance Fit, Pressure Fit
C. Clearance Fit, Tolerance Fit, Interference Fit
A. Clearance Fits, Interference Fits, Transition Fits
What does the term “fit” refer to in engineering?
A. The classification of tightness or looseness between two mating parts
B. The maximum and minimum dimensions of a part
C. The method used to assemble parts in machinery
A. The classification of tightness or looseness between two mating parts
What happens with components that have a clearance fit?
A. There is always some play after assembly, and they can be assembled with light hand pressure or without force.
B. The components are tightly joined with no movement after assembly.
C. The components are difficult to assemble due to excessive tightness.
A. There is always some play after assembly, and they can be assembled with light hand pressure or without force.
What are the two subcategories of clearance fits?
A. Running and Free Running
B. Tight and Loose
C. High tolerance and Low tolerance
A. Running and Free Running
What is the characteristic of an interference fit?
A. There is some play between the components after assembly.
B. The inner part is larger than the part into which it fits, causing tight contact.
C. The components can be assembled by light hand pressure or without force.
B. The inner part is larger than the part into which it fits, causing tight contact.
What is a characteristic of a driving fit in interference fits?
A. The parts are pressed together with a machine.
B. The parts are assembled by tapping together with a hammer.
C. The parts are held permanently using heating or cooling methods.
B. The parts are assembled by tapping together with a hammer.
What is the defining feature of a force fit in interference fits?
A. The parts are assembled by driving them with light hand pressure.
B. The parts are forced together using a press, with a larger interference than a driving fit.
C. The parts are heated or cooled to hold them in place permanently.
B. The parts are forced together using a press, with a larger interference than a driving fit.
In a shrink fit, how are the parts joined?
A. By driving them together with a hammer.
B. By forcing them together with a press.
C. The outer part is heated, or the shaft is cooled to create a greater interference and hold the parts in place permanently.
C. The outer part is heated, or the shaft is cooled to create a greater interference and hold the parts in place permanently.
What are the three sub-categories of interference fits?
A. Clearance Fit, Tight Fit, Loose Fit
B. Driving Fit, Force Fit, Shrink Fit
C. Loose Fit, Tight Fit, Transition Fit
B. Driving Fit, Force Fit, Shrink Fit
What is a transition fit in terms of mating parts?
A. A fit where the parts are very loose and have a significant gap between them.
B. A fit where the parts are almost the same size, with very small differences in size, achieved with finely finished and accurate surfaces.
C. A fit where one part is larger than the other, causing interference and no movement.
B. A fit where the parts are almost the same size, with very small differences in size, achieved with finely finished and accurate surfaces.
What is tolerance in manufacturing?
A. The total amount of variation in the size of a part.
B. The average size of a part.
C. The allowed weight of a part.
A. The total amount of variation in the size of a part.
What is bilateral tolerance?
A. When variation in size can occur only in one direction (either above or below).
B. When the amount of dimension variation can be above or below the design size.
C. When variation is allowed only within a set range, both above and below the design size.
B. When the amount of dimension variation can be above or below the design size.
What is unilateral tolerance?
A. The variation in size that is allowed only above the design size.
B. The variation in size that is allowed only below the design size.
C. The amount of variation allowed in only one direction, either above or below the design size.
C. The amount of variation allowed in only one direction, either above or below the design size.
How many grades of accuracy does the British Standards System provide for holes and shafts? A. 16 B. 20 C. 28
A. 16
Which system provides 21 hole classifications and 21 shaft classifications? A. ISO 286 B. Newall System C. British Standards System (BS)
A. ISO 286
What does ISO stand for? A. International Standards Organization B. International Standardization Organization C. International Standard Organization
B. International Standardization Organization
What does ANSI stand for? A. American National Standard Institute B. American National Standards Institute C. American National Standardization Institute
B. American National Standards Institute
Why is the hole-based system more commonly used?
A. The shaft is made with a tolerance range that is easier to control.
B. The hole is made with high and low-limits, which makes it easier to measure and fit.
C. The system is less expensive to implement than other systems.
B. The hole is made with high and low-limits, which makes it easier to measure and fit.
What does the BS 4500 system standardize?
A) Tools for cutting metal
B) Limits for hole and shaft sizes
C) Types of materials
B) Limits for hole and shaft sizes
What letter is used for tolerance positions in holes?
A) Lowercase letters
B) Capital letters
C) Numbers
B) Capital letters
What does “deviation” mean in tolerances?
A) The difference between a size and the corresponding basic or nominal size
B) The fit between a shaft and a hole
C) The upper limit of a hole’s size
A) The difference between a size and the corresponding basic or nominal size
What does “IT” stand for in tolerances?
A) International Tolerance
B) Internal Thread
C) Interference Tolerance
A) International Tolerance
What does “Shaft Basis” mean in tolerances?
A) A system of fits relating to the nominal shaft size
B) A type of clearance fit for all shafts
C) The difference between shaft and hole sizes
A) A system of fits relating to the nominal shaft size
Which fit represents a slight interference fit?
A) H7, k6
B) H8, f7
C) H7, g6
A) H7, k6
How are allowable wear limits determined?
A) Based on the inspector’s experience
B) Using tolerances provided by the manufacturer
C) By measuring clearance only
B) Using tolerances provided by the manufacturer
What does the schedule of fits and clearances specify?
A) The color of parts
B) Limits on wear and characteristics like ovality, bow, and twist
C) The weight of the parts
B) Limits on wear and characteristics like ovality, bow, and twist
Which fit is used for turbine blades in the assembly of an engine?
A) Heat/Shrink fit
B) Press fit
C) Clearance fit
C) Clearance fit
What is it called when the centerline of a shaft is not straight?
A) Twist
B) Bow
C) Deviation
B) Bow
What is the effect of a bowed shaft or tube when rotating at high speeds?
A) It improves the performance of the engine
B) It causes vibration, leading to mechanical failures
C) It helps in smoother operation of the machine
B) It causes vibration, leading to mechanical failures
What is it called when a shaft or tube isn’t straight and has a misalignment along its centerline?
A) Bowed
B) Bent
C) Twisted
A) Bowed
What happens if a shaft is twisted beyond its elastic limit?
A) The twist disappears after the force is removed
B) The shaft stays twisted even after the force is removed
C) The shaft becomes weaker but straightens
B) The shaft stays twisted even after the force is removed
What is the cause of twist in a shaft?
A) Applying a torsional (twisting) force
B) Applying heat to the shaft
C) Applying pressure on the shaft
A) Applying a torsional (twisting) force
How can you check the twist of a square-sectioned shaft?
A) Use a feeler gauge
B) Use a dial test indicator on a surface table
C) Measure with a micrometer
B) Use a dial test indicator on a surface table
Which of the following are the four dimensions typically covered in wear tables?
A) Dimension New, Permissible Worn Dimension, Clearance New, Permissible Worn Clearance
B) Dimension New, Permissible Worn Dimension, Maximum Torque, Clearance New
C) Dimension New, Clearance New, Maximum Torque, Fatigue Limit
A) Dimension New, Permissible Worn Dimension, Clearance New, Permissible Worn Clearance
What is the definition of “wear”?
A) The addition of material to a surface due to friction
B) The removal of material and deformation due to mechanical action between moving surfaces
C) The smoothening of a surface over time
B) The removal of material and deformation due to mechanical action between moving surfaces
How can bow in a shaft be checked?
A) Using a micrometer to measure the diameter
B) Using a straight edge and feeler gauges to measure maximum clearance
C) Measuring the shaft with a dial indicator
B) Using a straight edge and feeler gauges to measure maximum clearance
What can indicate that a shaft has been subjected to a high torsional load?
A) Visible marks engraved or etched at each end
B) Wear and tear on the surface
C) A loose shaft
A) Visible marks engraved or etched at each end
What is one method used to measure the amount of twist a shaft has been subjected to?
A) Vernier caliper
B) Strain gauges
C) Micrometer
B) Strain gauges
What causes ovality in a shaft or hole?
A) Friction or linear movement
B) Excessive temperature
C) Sudden impact
A) Friction or linear movement
What tool can be used to check a hole for ovality?
A) Go/no-go gauges
B) Micrometer
C) Dial indicator
A) Go/no-go gauges
Why should you check for ovality before bow when inspecting a shaft?
A) Bow measurement results may be inaccurate if ovality is not checked first
B) Bow is easier to detect than ovality
C) Ovality is less common than bow
A) Bow measurement results may be inaccurate if ovality is not checked first
What is the main purpose of a Dial Test Indicator (DTI)?
A) To measure temperature variations
B) To determine the amount of movement and roundness in precision machined parts
C) To calculate the weight of components
B) To determine the amount of movement and roundness in precision machined parts
What tool is commonly used to measure twist in a shaft?
A) Vernier calliper
B) Feeler gauge
C) Dial Test Indicator (DTI)
C) Dial Test Indicator (DTI)
