DIFFERENCE BETWEEN DIMENSIONAL TOLERANCE AND GD&T

Hello friends

My article today will be a bit short.

You may be thinking; "What would happen if we gave an example of 110 mm. ±0.2 in the design? Why do we need to give perpendicularity, parallelism, planarity, etc.?

The answer is below;

A drawing without GD&T, with only dimensional tolerances:

And the part that the manufacturer will give you;

Result: The manufacturer delivers the part to you, when you see the part you immediately think that the manufacturer did something wrong, but guess what, all the dimensions are within tolerance!

I hope I was able to explain the difference between Dimensional Tolerancing and GD&T.

The technical drawing above should look like the one below with GD&T applied.

Images taken from: Dimensioning and Tolerancing Handbook by Paul J. Drake, Jr.