Eyech 16pcs Dowel and Tenon Center Transfer Plugs Point, Drill Center for Dowel and Tenon -1/4", 5/16", 3/8" and 1/2"

Let me say these are a fine set of dowel centers if you live in a metric world, where you can go to your hardware store and buy metric drill bits and dowels in metric sizes. I don't. I have lots of imperial drill bits and dowels, and they sort-of-work with these dowel centers, but the next time I'm back in my local hardware store, I'll buy a 2nd set of GENERAL imperial dowel centers to have on-hand. The 3/8" metric centers are half a 64 oversize so you have to hammer them in and them carefully wedge them out -- not easy in white oak hardwood, and they leave an oversize holel to receive the dowel. With enough glue, they'll serve the purpose, but I'm looking for a dry fit, so they're a tad "loose". The registration is excellent, however. For imperial use, I'd rate these as 3 stars, for metric, they're five, so I'm splitting the difference.

Not true to size, 3/8 is 25/64 1/2 not even close 3sizes smaller, but i make my own dowels so will adjust