Blue Print Tolerance Block

Yes.

Yes.

This is intuitive. The inside radius can be sharp, or 1/4". In other words, it doesn't matter. If it did, the feature would be toleranced individually.

What document? They all have tons of information on defining things that are critical to the function of the part. If not, the tolerance block applies.

You would struggle to find two differnt companies doing things the exact same way. It boils down to, do you understand what the designer wants if you had to make it. If yes then his job was done correctly. Generally prints 'over tolerance'...and there are standards that most engineers follow.

From the information you supplied, it sounds like 0-1/4" radius is acceptable. I suggest you determine the application for this shaft and discuss this with your customer. Zero internal radii are good locations to initiate fatigue cracks. The more you know about the application, the better you can help your customer to make a high quality part - in spite of the specification.

Theoretically, yes, it would appear that, per the drawing, the fillets could be 0 to 1/4".

However, in my experience, I would say this is just typical oversight on the part of the person who created the drawing (which probably wasn't passed through a drawing checker) and/or the people who created the drawing format and tolerance block.

I don't know what field you're in or what kind of a cylindrical part you have but I can't imagine a drawing of a machined part using a fractional dimension for a feature. I would probably recommend the fillet be dimensioned or specified with a decimal dimension (ie, 0.12 or 0.125) and let the decimal dimension tolerance control it.

OTOH, a lot of CNC shops pretty much ignore all but special case tolerances on drawings anymore. We're getting really sloppy on our drawing documentation here in the US nowadays.

And tolerance stackups? Whatarethey?

Hooker <-- who tends to be old fashioned anal about drawings done professionally

^^ Sloppy..I agree.