Threaded wood insert help needed

[Scuffcakes]

I purchased some brass threaded wood inserts and Lowes thinking I'd give 'em a try for neck mounting.  Before I mangled my neck, I figured I'd try 'em out on a spare piece of wood to see how it goes.  I drilled a 3/16 hole which looked like the size of the insert.  When I went to screw it in the hole with a flat screwdriver, after about 1 turn one side just snapped off.  Thinking that I must have been putting pressure on it at an angle I tried again with another hole and another insert and paid particular attention to keep everything lined up as straight as possible.  Same result.  It seems that a much larger hole wouldn't give the threads much wood to bite into.  Any ideas on what I am doing wrong?  Should I look for higher quality inserts?  Any help would be appreciated.

 

[Patrick from Davis]

Stainless is the way to go, brass ones tend to crumble, as you have found out.  Mayfly, Cagey, and Skuttlefunk have all done this process and would have more insight into the pitfalls.
Patrick

 

[Danuda]

I did this on one of my scratch builds.  Do not use the brass ones, you need stainless steel.  Brass is too soft for hardwoods and will snap off.  The second thing you need is a drill press or to make a jig to turn your drill into a drill press.  It is very important that it goes into the hole you make 100% straight.  Doing it by hand just doesn't work.  I bought my stainless steel ones from McFeelys (sp?)  They also sell the adapter for screwing them into the neck.  Every attempt I made to do it with a hand drill failed.  I am sure you might be able to do it if you were careful and lucky with a drill, but do you feel lucky 4x?

 

[mayfly]

I always use threaded inserts for necks.  Absolutely required for my B-bender teles.  Was handy for the 12 string as well.  It's not that hard, but please don't use brass.  I've used these inserts on 6 guitars with great success:

http://www.onyxforgeguitars.com/Insert%20kit.html

I cannot vouch for others.

Some notes:

1 - use a drill press!  for both drilling and installing.  The instructions for the kit above says you don't need to.  Don't believe it.  Use the drill press.
2 - use the right tool for installation.  For the slotted ones, there is actually a funny shaped special tool that you need to get.  For the ones mentioned above, you just need a hex tool.  I used a cheap hex key of the right size cut in half.
2 - please wax the threads of the inserts.
3 - you'll need to flush sand after installing the inserts because the wood will pull up a bit around the hole.

There's a few pictorial installation threads here - one of which I did for Kashmir.  Just have a search and you'll find them.

 

[Scuffcakes]

Thanks for the advice guys.  I'll have a look at those threads and start researching stainless inserts.  I do have a drill jig but no press.  I'm also pretty dang steady with a hand drill since I use one all day for my job.  Rest assured I'll still do all kinds of practice runs before doing the neck.  I might just end up going with the ol' wood screws if this turns out to be too ambitious for me.

 

[Cagey]

I've had trouble with the Inserts Lowe's sells, too. They're too flimsy, as you've found, at least for hardwood.

I get mine from McMaster-Carr. I've used both brass and stainless to good effect, but prefer the stainless any more.

The inserts look like this...

It has an 8-32 internal thread and requires a 1/4" pilot hole.
The brass P/N is 90016A009 and they cost $8.79/pkg. (25 parts)
The SS P/N is 95807A100 and they cost $2.80 each.

In either case, you need a power driver. Trust me, you'll never pull this off with a screwdriver. With wood as hard as necks are made of, the insert will fight you tooth, fang and claw, even with the tool. You'll need a variable speed drill motor as well. The tool looks like this...

It's their P/N 94110A120 and it costs $9.26.

For screws, you want some philips oval head SS machine screws. Depending on whether you've got a standard or contoured body, and whether you've had the "720 mod" done to it, the screws need to be 8-32 x 1 1/4", 1 1/2", or 1 3/4".

They look like this...

1 1/4" 91802A201 $9.06/100
1 1/2" 91802A203 $7.08/50
1 3/4" 91802A204 $7.60/50

I strongly recommend you use a drill press for the holes. They need to be perfectly perpendicular to the neck, and you have to be ultra-careful you don't drill too deep and run into fretboard.

Also, when running them in, be sure to wax the threads and run the drill motor very slowly with plenty of down pressure on the part. As I mentioned earlier, they're going to fight you.

If you want to avoid the fight, you can pre-thread the hole with a bottoming tap. I recently started doing this, and it works well. It's an odd-sized tap, though, so finding it locally may not be easy. For these parts, it's a 5/16-18 bottoming tap. Using the tap also prevents the blistering Mayfly mentioned.

 

[Patrick from Davis]

The stainless ones McMaster sells I believe are EZ Lok, you can get them from Amazon as well.  The tool for inserting the inserts is from Ez Lok, I got one from McMaster.  There are a lot of different types, but to use the threading approach Cagey mentioned, the 303 stainless for metal work out.  You can get the 5/16 18 bottoming tap on eBay for 5 or so bucks.  You can also use another tapered one to start the treads, but it will not make it to the bottom of the hole.  They suggest three taps for metal applications, two different tapers, and then the bottoming.  With the wood, just go a ways, back up clean it out and start again.  They suggest an F size bit (0.257 in), or slightly bigger than 1/4 in.  I am assuming 1/4 would be fine.  Again, wax on the threads of the insert will stop it from binding in the wood.
Patrick

 

[Cagey]

Wow. My shopping skills must be shot to shit. When I bought my tap, I had a helluva time finding it and paid a helluva lot more when I did.

 

[Patrick from Davis]

At work we go through a lot of tools, and odd ones.  We are able to use eBay to find things cheaper.  For grant funded work, this can mean an extra 6 months with the savings of money, if we work at it.  So, we work at it.  For that kind of stuff, I always check eBay.  Most of the places I buy from are stores and they are dependent on good feedback for timely transfer of their money.  So if we don't need the tool that day, off to eBay we go.  They have cleaned up a lot of the wild west aspect of the auctions, and we have been disappointed very few times.
Patrick

Ahh, it is about 10 bucks with shipping, but that is not outrageous for a less used tool.

 

[stubhead]

There's two entirely different types of inserts. One of them has very coarse threads and are "self-tapping", called "jam nuts" by some. And the others, like what  Cagey pictured, are designed to work ONLY with pre-tapped threads. I hope this flashes to this picture?

https://www.google.com/#hl=en&gs_nf=1&tok=f80Q-cqAutNUbmYW_kBzKw&cp=10&gs_id=an&xhr=t&q=threaded+inserts&pf=p&output=search&sclient=psy-ab&oq=threaded+i&gs_l=&pbx=1&bav=on.2,or.r_gc.r_pw.r_qf.,cf.osb&fp=14d3625335d3880b&biw=1173&bih=753

Pix on the right side - the two top ones and the lower left ones are designed for pre-threading, the rest are self-threading. (If the rest of my life doesn't keep leapfrogging my project) I'm working on a guitar in which everything is modular, i.e. the pickup mount will let me use any combination of pickups, I just have to change the "pickguard" that holds them, the bridge with be changeable etc.

I'm using the tiny little 4-40 brass inserts for the pickup plate, because there's very little need for strength there. For the swamp ash, alder or mahogany bodies. I got some of the "jamnut" type inserts from Skuttlefunk on the forum. But these will only be used to mount bridges and tailpieces on the softer woods. For the harder woods - maple and walnut - I'm going to use the inserts that have to be tapped. I'm using the #319-3 here:

http://www.catalogds.com/db/service?domain=ezlok&command=locate&category=thin_crbn_unc

By the way, I personally see NO point in using stainless steel, just plain old steel is good enough. If the neck joint of my guitars get wet enough to make a difference, I'll have bigger problems than that. But NO brass (in a load-bearing situ) and NO zinc. That Onyx Forge site that Mayfly linked to uses zinc inserts, and considering that using something stronger isn't going take to any longer, and won't cost but a few pennies more... The best place I found to get the E Z Loks was, oddly - Amazon.com!
http://www.amazon.com/E-Z-LOK-Thin-Wall-Threaded-Insert/dp/B002WC8SX0/ref=sr_1_20?ie=UTF8&qid=1342315901&sr=8-20&keywords=ez+lok+threaded+inserts+5%2F16+-+18

$12.50 for 10, buy two =$25 = free shipping... Yay!

There's a good overview of using these E Z Lok ones here (and the same size as above):

http://www.philtone.com/inserts.html

And, not coincidentally, both my soft wood (Skuttlefunk) and hard wood inserts take the same size bolt.

 

[Scuffcakes]

I strongly recommend you use a drill press for the holes. They need to be perfectly perpendicular to the neck, and you have to be ultra-careful you don't drill too deep and run into fretboard.

I don't have a drill press available.  Do you think a doweling jig could be used?

 

[Cagey]

I strongly recommend you use a drill press for the holes. They need to be perfectly perpendicular to the neck, and you have to be ultra-careful you don't drill too deep and run into fretboard.

I don't have a drill press available.  Do you think a doweling jig could be used?

Not the ones I've seen. For one thing, they're generally designed to center up holes on an edge, not place them in two dimensions on a plane. Neck heels are not edges and the mounting holes are nowhere near center. For another, you wouldn't be able to see the existing hole and it's important that you do.

You almost have to think of this as metalworking. The wood is very hard, so hole placement and orientation is critical. There's no slop allowed like there is with wood screws, which will chew their way into just about anything in the area that resembles a hole. If the insert threads don't mate up with the machine screws, the insert won't move to accommodate - it'll just cross-thread. Then you get the fun project of removing the insert, redrilling the hole, gluing in a dowel, redrilling in the right place the right way, and reinstalling the insert.

Incidentally, you sorta need more than just a drill press - an X-Y cross-vise is needed to keep the neck in place and perpendicular to the drill, like you see here...

They're not terribly expensive, though. Tough to spend much more than about $50 unless you're getting something you might use on a mill.

 

[Scuffcakes]

Thanks for the info Cagey.  I'm gonna do some research, grab some inserts and do a little practicing.  I install Heli-coils in 2"-3" thick steel on a regular basis with a hand drill so I'm thinking this can't be much more difficult.  I can see how a doweling jig wouldn't work but I have a flat-bottomed jig that can be clamped on and should help keep it straight.

I actually already have a 5/16"-18 bottoming tap in my collection right now.

 

[Cagey]

If you've got some pieces of scrap Maple laying around, they'd make good target practice for this exercise.

 

[Scuffcakes]

If you've got some pieces of scrap Maple laying around, they'd make good target practice for this exercise.

Hey!  The dining room table is a solid maple top.  That would probably be perfect to practice on!

 

[Updown]

If you've got some pieces of scrap Maple laying around, they'd make good target practice for this exercise.

Hey!  The dining room table is a solid maple top.  That would probably be perfect to practice on!

Perfect    :icon_thumright:

Just go from underneath, NO one will ever know ......... except us here  :laughing7:

 

[Scuffcakes]

Check out the modified doweling jig.  It ain't perfect but it's a whole lot closer than free-handing it.

 

[Cagey]

It's gonna work like a charm, BooBoo!
Ok, Yogi...​

 

[ezas]

I'm a little late to this discussion but I can add to it.

I have used three kinds of inserts with 3 different types of threads. I did all of them with a drill press. I drilled the holes. Then counter sunk the holes to help guide the insert. I used the little widget I cobbled together in the fastener Aisle at Home Depot. As you can see from the picture I waxed the threads.

I was able to source the stainless steel ones locally in Los Angeles. Another (the middle one) came from Orchard Hardware, and the last one from Lowes.

 

[ezas]

Incidentally, you sorta need more than just a drill press - an X-Y cross-vise is needed to keep the neck in place and perpendicular to the drill, like you see here...

I just used a drill press.

What I did was level my drill press base and my drill press table. I also checked that the drill was at right angles to the table.

Then I used some cork on the edges of my fret board to give me a clamping surface that was flat. Then I played around with clamps until the face of the neck was also level. This also required that I move the table around to position the clamps and neck.  I used a drill bit to get my neck in the right place with the hole lined up with the drill bit. This was a smaller bit that just fit in the wood screw hole in the neck. Once the neck was set in place it stayed set until the hole was drilled for the insert, countersunk, and the insert pressed in.

I drilled the hole for the insert and then changed from the drill to a countersink and countersunk the hole. Then I put my little tool press in and pressed the insert in.

In the picture below the bubble level is actually dead center. It's the angle of the camera that makes it off a little bit. I've done three necks this way and the neck screws go right in on all the holes.