I'm in the process of making a few jigs for drilling the lab bolt holes in the neck heel, and needed a little bit of info...
What size holes should be drilled for the smaller (prewar, I think) lags, and the larger (50's, I think) lags?
I have to order some metal drill bushing, and wanted to know what size drill bit to order them for.
Google search: how to size a drill bit to a screw.
I would chose a tap drill diameter that is the same as the the root diameter of the thread on the end of the lag screw that you intend to screw into the heel of the neck. You should be able to measure that root diameter with a dial or digital caliper.
Drill an 11" hole.
#8 wood screw 1/8" straight bit
#10 wood screw 9/64" straight bit
You can find this info online- and you will find different recommendations. The above is from an old chart I have, so you should verify what works for you. Experiment first with some scrap wood and do what you think works out best.
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