Orientation Tolerance 1

[00005]

Hi everyone,

I have an indicator shaft with an hexagonal head on one side and a slot on the other side. The flat surface of the hexagon has to be parallel with the slot. The manufacturer insists on showing the tolerance on the drawing in order to get the right orientation for the slot and hexagonal head. Is it necessary to put that tolerance on the drawing? What is the symbol for that? I have little knowdleges of GD&T.

Thanks

 

[aamoroso]

I would probably go with Parallelism (Geometric tolerance). This is the most effective, assign the slot wall as the datum and the tolerance on the hex flat to it as parallel but remember this is a 3 dimensional tolerance, that means the wall of the slot and and flat of the hex must be parallel planes not just the orientation of the two edges.

or

Simply state in a note on the drawing that the specific edge of the hex must be parallel within +/- x Degrees of the edge of the slot (this allows the walls to be tapered but still hold orientation).

There are other options as well, but use what is necessary, if you over constrain the orientation the cost of the product will go up. Use as much tolerance as you can allow for the part to function properly.

Fill what's empty. Empty what's full. And scratch where it itches.