Mandrel Note

The Ring Laboratory widget gives the Actual Aspect Ratio, as measured with calipers. All other widgets currently use Mandrel Aspect Ratio, which is smaller than Actual (measured) AR. If you opt to "use B3 Ring sizes," note that the listed ARs in that drop-down menu are Mandrel Aspect Ratios, based on the wire diameter used for each metal. We are working on adding a feature that will allow you to also search by Actual ARs for B3 rings.

For more information on this very important distinction, see Actual AR vs Mandrel AR in our FAQ.