The pros and cons of using guitar neck inserts have been debated many times on guitar forums. While some say they do not hear a difference in sound with inserts, I do. I have tested and used neck inserts for years and I install them on every guitar that I build.
I first read about neck inserts 25 years ago in an article featuring Danny Gatton, who remains one of my favorite players of all time. His guitar builder was selling an insert kit, so I ordered a set and installed them on one of my own guitars. I had played this guitar for years and was very familiar with how it sounded. Once installed, I noticed an increase in the sustain of the note and the guitar seemed to ring out more.
The down side of the inserts was their size. Installing a 10/24 insert didn’t leave much wood between the side wall of the neck heel and the insert, and I had to enlarge the four neck mounting holes in the body.
I turned to my friend Charlie McVay of McVay Benders. Based on his experience as a machinist, he suggested going to an 8/32 thread so I would have more wood on the neck heel and not need to enlarge the holes. At first, I used cheap, brass self-tapping inserts from a local woodworking store. These worked essentially, but the brass was soft and the inserts were difficult to line up properly.
Charlie then recommended steel inserts from a company called EZ-Lock. These include adhesive built into them that is activated by the friction of installing them. Charlie hooked me up with the proper bits and taps and showed me the correct technique of how to drill the holes, countersink the opening, and use the tap to cut the threads into the wood (much like tapping threads into metal).
Why I Use Neck Inserts
Installing the inserts takes additional time and it’s an added expense as opposed to just drilling a hole and installing a wood screw. So why do I go to this trouble for something a player doesn’t see?
1. The bolt will never strip out. Wood screws will eventually strip out when the neck is taken on and off regularly.
2. I love how it improves the sound. I have tested my guitars using regular wood screws and then went back and installed inserts. Every time I have done this, I have heard an increase in the sustain and a ringing quality to the sound of the guitar.