I need to put a 1/4"-20 screw securely in a .385" square hole. 1/4"-2- to 3/8"-16 adapter show up when I ask for 1/4"-20 to 3/8" bushings. I need a tight square, not threaded 3/8". I could I suppose do a .38" x .38" square, then drill and tap it, but this does not seem this odd an item to buy.
I managed to make the square so it was a press fit into the spider. Then I drilled a pilot hole in the center. Whoops! Not quite centered. I could not drill the .203" hole for tapping all the way through because I had forgotten to put something under the block in the mill vise, so I went to the drill press and ended up with a hole out the side. Let me try this again in the morning unless someone points me to a bushing.
McMaster-Carr, purveyor of everything, has female threaded standoff, aluminum, 1.4"-20 fully threaded, 1" long, 1/2" diameter. So just turn it down on the lathe to .385" and press in, I think,
My first thought was a square nut, but a quick check has them at 7/16 across the flat on 1/4-20 threads. Milling one down is probably more trouble than drilling and tapping....
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