Making a 'roller' for a roller stand the other day. I noticed the same issue, drilling a 1/4" hole and expecting it to turn on a 1/4" bolt. I could barely get the bolt in (without using a hammer). So I measured some bits to see if I could find an oversized one... all of them were undersize! I finally found a knurled punch that opened the hole a bit. I guess the knurling added a little width to 1/4" material it was made from???
Sent from my Hallicrafters S-40 using morse code.