On 12/05/2018 06:55 AM, Frank wrote:
Learned this yesterday. What I measured as one inch pipe was actually
3/4 inch.

https://www.pvcfittingsonline.com/re...e-pvc-is-this/

https://www.engineeringtoolbox.com/a...pes-d_305.html

Same as black iron or steel, unless you get into the copper sizing
variations:

https://www.sizes.com/materials/pipeCopper.htm

Whenever possible I bring a sample of what I'm working with me when
buying plumbing stuff.