E-Z LOK 400-4-CR Threaded Inserts for Wood, Installation Kit, Stainless Steel, Includes 1/4-20 Knife Thread Inserts (6), Drill, Installation Tool

I recently built myself a custom Stratocaster with a black limba body and solid rosewood neck from Warmoth. These guitars are referred to as having bolt on necks when they actually use wood screws. That term has always bothered me. For a better, more solid connection these inserts are perfect and the guitar will actually have a bolt on neck. A solid neck to body connection is crucial for tone transfer and this method is considered superior to just using wood screws. It's a little tricky getting everything aligned properly before drilling the holes for the inserts but measure twice and drill once is the way. Clamp the neck to the body and use the e strings as alignment guides and you can't go wrong whej pre-drilling the holes for the inserts. I recommend gluing these inserts in with a good marine epoxy for maximum hold.

I had struggled with brass versions of this type of inserts and the zinc variation with the hex drive. These tool included with this kit ensured alignment and the stainless material didn’t deform like the brass. It was cheaper to buy two kits to get the quantity of inserts I needed.

I am putting these in a piece of Mahogany for a guitar project in working on. I first tried some brass ones from a local hardware store without the tool. The top area shattered each time and I had to extract them. This kit with the tool has gone in so much easier each time.

This is a slick system. The drill bit seems too large for the inserts if you look at them overlapping, but it is just the right size, especially in hard wood, like Oak. If you use it in a soft wood, be sure to drill the pilot hole deep enough, or you will likely strip the wood threads created on entry trying to tighten it after it contacts the bottom of the hole. Also, I used a T-bar style hand driver to drive the inserts into the hole. The custom driver bit they provide is notched to fit small slots on one side of the insert, and this fit easily into my chucked hand driver. It works really well. Hand driving them gives you the control needed to get them started perpendicularly into the hole and then on until tight just below the surface of the piece. Very satisfying result. Of course, you may need to drill an additional distance into the piece with a 1/4 inch bit PRIOR to driving in the inserts in order to accommodate the length of the 1/4 inch bolt you will be using.

If you are using this for hard wood DON’T. I have been using threaded inserts for 10 years. I decided to use EZ Locks because the actual threaded inserts are super high quality. But, the tool to insert them is trash. The threaded tool to screw them into place broke off the very first time I used it and I was extra careful when screwing down. I set my drill to a very slow speed and made sure not to torque it to hard. Second - the other tool. The 500-2 tool with the lip for the slots on the threaded inserts broke the first time I used it as well. I honestly don’t even know how I would insert these. I can’t find a tool that can hold up to screwing them down. Last, they are impossible to install straight. The threads on the inserts don’t allow them to start straight. Overall. I will never use these again. They look great and overall they look impressive. But, they are not worth the money or the hassle. On top of that I was sent one package with a 17/64 drill bit and 5 inserts instead of 6. I reordered and the replacement had 4 inserts instead of 6. I’m not sure what’s going on here but there is a major quality issue with this product.

I was using these for river table legs, to insert into VERY hard hickory wood. The 25/64 bit was VERY snug. Had to open it up to 13/32nds in some spots. What I found worked best was a stainless steel 1/2" inch bolt to put them into the wood. Save the special proprietary tool for when you mess up and need to pull one out. The brass inserts are very prone to chipping with too much torque on the EZ Lok insertion tool, but the 1/2" 1/4" 20 bolt worked well to insert. I would buy again now that I know how to use.

Worked great to fix stripped out hinge screws in wood on my boat. I had no trouble with the included installation tool. I drilled the pilot holes using the included bit and made sure the hole was at least as deep as the insert is long, and the inserts went in very easily. I’d guess that people who broke the installation tool didn’t drill their pilot holes deep enough. I just wish they weren’t so expensive, and that you could buy more inserts separately and save money.

The kit is great but use a drill press if you have one to assure they go in nice and straight.

I liked the fact that the kit comes with the proper size drill and insertion tool to screw the insert in. I used it to attach an electric guitar neck to the body so I could use threaded screw instead of wood screws.

Used on a wooden deck to secure a canopy. Easy to use but you must be careful to get the insert straight.

The insert driver works very well. VRB