Acoustic Guitar Construction

If you want them to screw into concrete, yes.
If you make the right hole in Mahogany, no. The bits normally have a screwdriverspace and they screw in quite easily. Maybe others have different opinions (as always), but I would buy me a few cigars for the bucks. Or you tip the beauty thats points out the way when you're lost.

Herman

Those fine thread inserts are not suitable for neck joints -- the course thread version has a smaller diameter. I do have that tool and it does work well -- the fine thread inserts are OK for flatwork, cabnetry etc. I believe I got mine from Woodcraft or Rockler for a lot less$$

I've been using those fine thread brass inserts and usually they go in okay, and I wick in CA around them to make sure they are secure, but this last time, in honduras hog, I had a heck of a time getting them to thread in, they did not cut so much as mush their way in.
Ken, which ones do you suggest? The aluminum with the really coarse threads?

Kevin

Kevin the fine thread works for you because your tenon is non-standard and wider than 3/4" -- LMII has the course thread brass inserts. Soon, I may offer a neck fastener package with the brass inserts, Bellville washers, and Allen head screws.

I totally agree with wicking the CA around the inserts.

This tool is useful! I chuck it up in my drill press to keep the insert going straight vertical - especially for the first couple of threads. I turn the chuck by hand while keeping down pressure on the handle.
And I always apply CA to the wood around the insert. It toughens the end grain on a neck.