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Question on seeing a + + tolerance

My keyboard graphics are poor, no doubt about it.

The clearest pseudo-verbal description of the Stated Linits format am coming up with at the moment is that the High Limit is written over a horizontal line, and the Low Limit written beneath that same line.
 
My keyboard graphics are poor, no doubt about it.

The clearest pseudo-verbal description of the Stated Linits format am coming up with at the moment is that the High Limit is written over a horizontal line, and the Low Limit written beneath that same line.

Yeah, that's usually how it's done if it's ever done on a print. I prefer the opposite, myself. I guess my brain just thinks in an ascending manner. I like low-high instead of the other way around.
 
Personally, John, I always liked this format:

3.500"/3.505"

I think this is what you intended to write as your latter option? Often would mark up my own sketches this way. Very little thinking necessary with that method. I never really had a problem with any of the tolerance styles though. Just had a personal preference for seeing the low side and high side dimensions directly.
I like that format, but in this day of programmed from step files there's another question....where do you model it?
Personally the answer for me is:
1. Exactly halfway between the max and min tolerances.
2. If you're not willing to do that, at least be consistent.

+/+ and -/- is valid, but even sent to 3rd party metrology it seems like 25% of the time someone misses one and reads it as +/-.
Better IMO to use the ISO fit class or whatever you want to determine your max/min, but then model it down the middle and have a symmetric or limit tolerance on the drawing.
 
I like that format, but in this day of programmed from step files there's another question....where do you model it?
Personally the answer for me is:
1. Exactly halfway between the max and min tolerances.
2. If you're not willing to do that, at least be consistent.

+/+ and -/- is valid, but even sent to 3rd party metrology it seems like 25% of the time someone misses one and reads it as +/-.
Better IMO to use the ISO fit class or whatever you want to determine your max/min, but then model it down the middle and have a symmetric or limit tolerance on the drawing.

Yeah, modeling can definitely be its own can of worms.
 








 
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