DIMENSIONING A 90 DEGREE ANGLE ??

[learningchecker]

Hello, We use ASME Y14.5-2009. We have two different opinions here.

Is a 90 degree angle ever dimensioned? There is an arc with a line tangent to that arc at 25 degrees from the vertical. There is another line on the otherside of the arc, tangent to that arc, which is 25 degrees from the horizontal. On the drawing the arc is dimensioned and the 25 degree tangent line from the vertical. Some want to dimension the other side from the horizontal at 25 degrees.

I say "No" because the lines are 90 degrees apart.

Does anyone know a "rule"?

Thank you for your help.

 

[CheckerHater]

Generally, a 90° angle applies where center lines and lines depicting features that are shown at right angles and no angle dimension is given on the drawing. This is called an implied 90° angle.
As your 90° angle is slanted, the perpendicularity is not obvious, and, more importantly, angle dimensions ARE shown on the drawing (25°), I say 90° angle is no longer implied.

 

[learningchecker]

CheckerHater,

This is a small simple part with only two views. There is only one angle dim of 25 degrees shown tangent to the arc. Just to be clear, you are saying the tangent line on the other side of the arc (which is 90 degrees from the 25, needs to be dimensioned?

 

[learningchecker]

The only info I can find on the internet is that 90 degrees is implied, but I am still looking.

 

[CheckerHater]

You say your company is “using” Y14.5-2009.
If there is a copy of the book available to use, check out Paragraph 1.4(i). It’s all you need.
And yes, adding another 25° dimension will make your intent perfectly clear.