1 Reply Latest reply on Nov 25, 2013 5:30 PM by Matthew Lorono

# implied 90 degree angle

Hi Guys, i have a question about how a drawing which is drawn per ASME Y14.5M should be interpreted. Sorry not sure if this is the right place but Im kind of out of option and would really appreciate the help!

In the drawing I have attached I need to know what is the interpretation of the center line and implied 90 degree angle on the A side?

Does it mean the top surface (that line A is covering) and the edge surface (That line C is covering) should make 90 degree angle or the center line and line B should make 90 degree angle on top view only? I think the answer is the latter but wanted to see what you think since I am in QA field. So if the side view is like below as long as center line and line B on A side are making 90 degree angle we are still ok even though top surface and edge surface are not 90degree.

(edge view)

I really appreciate you guy's help!

• ###### Re: implied 90 degree angle

90deg angles are implied for 90deg angles.  You do not need to add 90deg dimensions unless there is some ambiguity (exteremly rare).  Standard tolerance for angles that is stated on your drawing still applies, so be careful.

Centerlines do not imply anything other than they are going through the center of something.  They do not provide you with any dimensions or tolerances.  If you do not dimension to them, they pretty much mean nothing, not even symmetry.  Just about the only thing you can assume in your example is that they are 90deg to the Line B.