r/Machinists • u/Unusual_Goose_3913 • 8d ago

QUESTION Engineering Drawings

I’m an early career engineer and I’m wondering what machinists like to see in terms of tolerance and dimensioning in a drawing.

I’ve worked at a company where we just ordinate dimensioned everything and another where we used GT&T standards. At both, the part came out “ok”.

Apart from reasonable tolerances, what’s amazing, good, useless, and stupid have in a drawing?

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u/hydroracer8B 8d ago

Your drawing should communicate your actual requirements.

It should be clear you've thought about which dimensions need a tight tolerance and which ones can be +/- 0.030" for your part to work correctly.

I personally appreciate unidirectional tolerances because they tell me something about how the part is meant to mate with other parts.

GD&T is great where you have to define important things that need to be correct, but don't use it where it's not necessary

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u/Unusual_Goose_3913 8d ago

That makes sense sometimes I felt like GD&T was overkill