# How to interpret tolerance in technical drawing

I'm trying to interpret the following mechanical drawing:

However, I struggle with the "tolerances" part. Shouldn't one dimension (like $$44$$ diameter) have one number attached to it, to indicate that tolerance? In this case we have two numbers, and I can't understand their meaning.

• It could be that it is $44_{+0.220}^{+0.420}$, indicating the extremes. Because this is probably from an exercise sketch which aims to teach how to correct input drawing tolerances, I can't be certain.
– NMech
Sep 22, 2021 at 15:36
• Do you mean that the diameter should be in the interval $[44-0.220, 44+0.420]$? Sep 22, 2021 at 15:47
• I'd guess it applies to the 25 (basic) ID ?? Is the part a collar? If so, +/+ on the ID would ensure clearance... If the OD had +/+, it would ensure interference -- possible in general, but then the 8/16 side hole feature would become inaccessible... I agree that it ought to be more clear Sep 22, 2021 at 16:20
• @alexp yes that was the intent of my comment.
– NMech
Sep 22, 2021 at 16:46