Metrology 150404a 150404b 150404c Flashcards
(51 cards)
The total deviation from basic size is called,
Tolerance
The difference between the upper limit of a shaft and the lower limit of a whole is called,
Allowance
Largest and smallest permissible size of a dimension is called,
Limits of size
The dimension from which the limits of size are derived by the application of Tolerance is called,
Basic size
The type of fit resulting when the limits given to the meeting parts will permit either an interference or a clearance fit is called
Transition fit
The most common system of limits and fits in North America.
Hole basis system
The size used for reference purposes is
Nominal size
The class of fit of those listed below that has the largest tolerance
Rc2
Rc4
Rc6
RC8
RC8
Which grade of Gage blocks is used for the shop floor inspections and set up?
Grade A S - 1
If producing a hole with a diameter of 2.5 in plus or minus 2 thou what would be the limits of size for a no-go plug gauge class y?
2.502 - 2.50188
To accurately position a workpiece in a repeatable manner using the 3-2-1 rule how many datum points are required?
6
Which tools are used as a reference to calibrate a ring gauge?
Gauge blocks and precision rollers
Quality control can be broken into which two groups?
Measuring and gauging
Three grades of Gage blocks and their applications
Grade 0 inspection standard
Grade AS-1 used in shops for parts set up and inspection
Grade AS2 shops looking for cheaper Gage blocks with tolerance is higher than AS1
Why use wear blocks?
Protect your gauge blocks from damage and abrasion
What materials are Gage Blocks made from?
Hardened steel ceramic and carbide
Hardened steel is cheapest ceramic and carbide last longer but cost more
Define limits of size
Maximum and minimum the sizes are allowed specified on the print. Don’t have to calculate, use sizes on the drawing.
Define fit
How the meeting parts fit together either clearance interference or transition
Define tolerance
Permitted variation in a part size the difference between the upper and lower limits of size the total amount size is permitted to vary
Define allowance
Intentional difference in size of mating Parts at their MMC. To calculate, subtract largest shaft from smallest hole
Define datum
Where most points are measured from the zero point
Define datum simulator
Simulated datum is established from a design datum
Two types of error in micrometre threads?
Periodic error and Progressive error
Two types of error in dial indicators?
Repetition error and Progressive error
