This comes up often as an issue with 3/4 in. dowel stock. I tend to select the smaller diameter stock if there is an assortment available. I would rather not mess with perfectly sized 3/4 in. bench holes. If length of dowel is a tight fit in the hole, I wrap some sandpaper around the dowel length and turn it a few passes with progressive grits from 120 to 220. This is what I do for my bench jigs. For individual bench dogs I undersize the length of dowel forming the bench dog using sandpaper wrapped around the length. Once bench dog fits a tad loose ,,I drill and insert a bullet catch into the side . This works extremely well and keeps bench dog from falling through yet maintaining a tight fit at any height. I like this approach as it makes the bench dog much more versatile in different dia. 3/4 in. bench holes.
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