Eng-Tips is the largest engineering community on the Internet

Intelligent Work Forums for Engineering Professionals

I am new to GD&T can someone please explain what all of these mean? Thank you so much 2

Status
Not open for further replies.

Gambler52

Mechanical
Feb 2, 2022
2
0
0
US
Drawing_2_bzvlty.png
Drawing_3_zoaktf.png
Drawing_1_vkbtah.png
 
Replies continue below

Recommended for you

1.6 Surface finish applies between points X and Y

"Know the rules well, so you can break them effectively."
-Dalai Lama XIV
 
At the top, CTQ means "critical to quality" and it signifies that the given callout (in this case parallelism) is very important -- perhaps for safety or functional reasons. Thus, it is to be verified after production and often this gets into statistical tracking.
The rectangular box next to that CTQ shows the GD&T symbol for parallelism (shown by 2 slashes), which means that the surface on the right side of that picture is to be parallel with respect to datum D (taken from the surface on the left side of that picture). The allowable deviation from perfect parallelism is 0.2 mm over the length of that right-hand surface.
 
Gambler: Belanger is probably correct when indicating the 0.2 dimension is in mm. However, I don't see anything in your depictions that indicate what the units are for the drawing as a whole (usually found down toward the lower right corner or maybe a bit toward bottom right-center). What it - and any other measurement OTHER THAN the surface finish symbol - means that the numeric value is in the units of the drawing (inches, millimeters, feet, miles, cubits, furlongs, etc.).

Converting energy to motion for more than half a century
 
Trailing zeros are not used on metric dimensioned drawings, so that would indicate the dimensions are in inches. However the dimension values would indicate a metric dimensioned part. The drafter needs to update the dimensioning to conform to standards.


"Wildfires are dangerous, hard to control, and economically catastrophic."

Ben Loosli
 
Status
Not open for further replies.
Back
Top