Q: I am looking to purchase dowel pins but are there standard tolerances?
A: Yes, tolerances for standard inch size dowel pins would be per the ANSI B18. 8.2 spec. They have a diameter tolerance of -0.00 / +0.0002 and length tolerance of +/-0.010. If different tolerances are required then you would want to call them out or send a drawing at the time of RFQ with what is needed.