What does counterbore/spotface and down arrow with a bar on top symbol actually means?
I was given an assignment with instructions that is worth a lot of our grade in my CAD class. We use AutoCAD 2015.
Hello,
Bore: is a cylindrical hole done with a top circular diameter.
Counter Bore: is a top circular diameter with a shamfer or a bevel, You can think of it as a housing for a screw to sit in, so that there is no difference between the part and the screw’s head.
Hope this clarifies things 😀
Based on the drawing, the counterbore symbol should indicate the diameter of the counterbore that sits around the actual hole diameter and the down arrow indicates how deep the counterbore goes.