Bolt on neck ferrules

[demonx]

I don't do much in the way of bolt ons and when I have it's been neck plates I used.

I've noticed people using fancy looking recessed ferrule looking things that have some sort of plug in the neck

What are these called?

What is the best type?

Educate me!

[Prostheta]

"Neck bolt ferrules" is as good as their name gets really!

They come in both plastic and metal however the differences (other than finish) is marginal as long as they perform their required function; to spread the pressure from the neck bolt/screw's head across a larger surface area. Steel, Brass, Titanium, plastic, no difference.

[curtisa]

I think the "plug in the neck" thing you're referring to are threaded inserts. Basically a cylinder of metal with wood threads on the outside for fitting into timber, and tapped metal threads on the inside for accepting a machine screw. Kitchen cabinet makers use them for bolting melamine carcases together.

I like to use the ferrules with regular wood screws. Gives the build a more no-frills look and allows some freeform sculpting of the heel which you simply can't do with a solid metal plate. Ibanez do the same thing with their All Access Neck Joint. Some builders perfer to go the ferrule + threaded insert option. There could be some kind of tonal voodoo associated with the inserts and machine screws - maybe it's due to the finer pitch threads on the screws allowing more clamping pressure between the neck and body than can be achieved with standard wood threads? A threaded insert also allows you to use different styles of bolt that aren't readily available as wood threads - allen heads for example.

Up till now I've used Allparts metal ferrules in black or chrome as required. I've just bought a bunch of cheaper no-name ferrules to try out. Given they're not much more than a glorified washer I can't imagine there'll be an awful lot of difference between them in quality.

[Prostheta]

I have used countersunk hex-head bolts with threaded Brass inserts a lot. In fact, the last bass I bought was retrofitted with these just because I hate the stupid Fender wood screw hangover.

Clamping pressure means nothing to me really. A neat neck pocket makes more difference than a quarter turn on the screws/bolts. The threaded inserts provide far more security than wood screws which will gradually start to become loose and less effective over time.

[demonx]

Your counter sunk bolts sound like what I've seen prostheta. Now just to source some in black

[Prostheta]

Cheat. Shop around for skateboard truck bolts or aftermarket bike components. They often come either powder-coated or anodised which is a better "look" for a guitar than black oxide or other nasty "industrial" finish.

[Prostheta]

I used four of these to secure a bolt-on neck for an eight-string almost eight years ago. Powder-coated yellow skateboard truck bolts and hard plastic ferrules. The guitar is still playing strong in the hands of its current owner to this day without any issues with the neck.

[bob123]

I use those ferrules and inserts on cheaper guitars, and, tone voodoo aside, I notice a relatively dramatic change in tone for the better. More sustain and resonance. I would do it to my more expensive guitars, but that whole "Resale" thing... Normally I use stainless steel into brass, which theoretically could have some corrosion issues, but here in the midwest, I don't think that would ever be an issue.

Edited November 12, 2013 by bob123

[Prostheta]

Ummm. Sustain and resonance are basic tone voodoo.

If anything using inserts improves on the inadequacies of wood screws but to call it a dramatic change is debatable. Certainly, if the wood screws were making a shoddy job of the neck/body coupling there would be an improvement but not one of dramatic proportions.

A lot of the time these perceived differences are just confirmation/selective memory biases. Either that or the marketing writeup really got its hooks in.

[Tim37]

For the best tone you have to use glue made by midgets in scotland

[rhoads56]

For the best tone you have to use glue made by midgets in scotland

If anyone wants some of this glue, I have gallons of it.

[Prostheta]

Made from boiled and rendered Scottish midgets?

[pan_kara]

Ummm. Sustain and resonance are basic tone voodoo.

If anything using inserts improves on the inadequacies of wood screws but to call it a dramatic change is debatable. Certainly, if the wood screws were making a shoddy job of the neck/body coupling there would be an improvement but not one of dramatic proportions.

A lot of the time these perceived differences are just confirmation/selective memory biases. Either that or the marketing writeup really got its hooks in.

How about next time someone does a neck modification like this they record the before & after dry guitar signal? Sustain is a measurable quantity..

[VesQ]

Aside from Scottish dwarfs. What size threaded inserts you would use on bolt neck?

[Prostheta]

Off the top of my head I think my bolts are M5 thread. A lot of threaded inserts are designed for low-density materials like chipboard, MDF, plywood, softwoods and plastics so it's somewhat difficult choosing the right ones. I can't remember which type the ones in the photo were but I got them from Harrison Silverdale in the UK. eBay is probably the easiest way to get them in reasonably small quantities.

I think Fagerholm over in Tampere has a barrel full of them still....

[demonx]

I couldn't find the "fancy" looking ones with some basic google searching so I've just ordered some basic generic recessed ferrules with standard neck screws from a luthier supplies so I can get these guitars moving along quickly and I'll have to look into the "fancy" ones soon

[Prostheta]

You have to be careful about the ones that you use. Some of them have teeth which are inappropriate for Maple and can easily split a neck's heel. Maple - for example - only needs short, fine-toothed inserts otherwise the sidewalls end up highly displaced as well as compressed. Mahoganies are probably more forgiving.

[demonx]

Will keep that in mind

[RestorationAD]

Sorry I am late to the party.

I use Steel 8-32 threaded inserts on guitars and 10-24 on Bass guitars. Watch the pilot holes and make sure they are the right size. Better to have to wik CA in than make it too tight. Use a drill press and the appropriate driver bit to install them. You need the drill press for downforce and to keep the insert straight as it threads into the wood. DO NOT USE a flat head screw driver unless you just like splits and mess. I covered this recently in my S9 thread.

I was getting them from mcfeelys.com because they had socket head version. These has been discontinued and replaced with ez-loc brand which requires a special driver to install with consistency.

I use Stainless Steel 8-32 (10-24) Socket Head screws in several lengths (1, 1.25, 1.5, 1.75) for neck bolts.

[RestorationAD]

For the best tone you have to use glue made by midgets in scotland

If anyone wants some of this glue, I have gallons of it.

I could use a few bottles... the stuff I have is made from Irish midgets (actually regular short irishmen but to the rest of the world "midgets") and it has a short open time because of the high alchohol content.

[acpken]

I could use a few bottles... the stuff I have is made from Irish midgets (actually regular short irishmen but to the rest of the world "midgets") and it has a short open time because of the high alchohol content.

Not to mention it's a very strange color too... green. Hard to camouflage on a natural colored top.

I read somewhere that someone made a tap out of a screw the same size and thread as the outside of the insert. This way, with the wood prethreaded for the insert, the insert and/or wood wouldn't get mangled if the insert driver slipped during installation.

ken

[Prostheta]

That would be of great benefit to anyone who regularly relies on threaded inserts. It's possible that it is a manufacturer-supplied tool since threaded insert's exterior threads are application-specific.

These are some interesting examples from the supplier in the UK that I mentioned:

Neck inserts:

http://www.harrisonsilverdale.com/fasteners/20130/D/125.html

http://www.harrisonsilverdale.com/fasteners/20131/E/126.html

They are self-tapping however RAD's caveats still apply. Their Spancert inserts look of potential interest for anybody wanting to employ threaded inserts for cavity covers, pickup height adjustment and other locations where wood screws are found.

[SwedishLuthier]

I experimented with making a thread cutter like Ken described as I always use (or used) threaded inserts but the force needed to turn the "threader" was extreme. I also use stainless steel M6 bolts with a Torx head. It is possible to destroy the wood with the pressure I can apply to that combo.

Nowadays I only use the treaded inserts for repairs. For the guitars I build I use this (no idea what it is calles in English) sandwiched between the fretboard and the neck wood. I rout a smal pocket for the top part in the neck wood. That take care of the problem with possible splits in the neck wood from installing the threaded inserts (and that has happened way to often to me in past). Another way to prevent splitting is of cause to clamp the neck hard from the sides while screwing in the inserts. And use slightly larger holes as RAD mentioned.

I have a "in progress" tread coming up that will show how I do things now. I'll try to post a pic here too.

[Prostheta]

The image attachment failed. I presume you mean t-nuts (http://en.wikipedia.org/wiki/T-nut)?

They're a great solution and yes, obviate a lot of installation issues. Realistically there is nothing stopping builders from inserting anything from long threaded hex standoffs to a stack of nuts in a drilled hole. I remember reading somewhere a while back on a non-guitar related subject about somebody making fasteners for a jig in this fashion. Three normal nuts were stacked end-to-end and fitted into a drilled hole. From the other side, a well-waxed bolt was mounted through and epoxy dropped over the nuts to secure them into the wood (well, HDF in that specific case).

Bringing this back around to DemonX's opening post, ferrules spread the load of the bolt or screw head which significantly increases the force the fastener can apply to the part being cinched in (the neck). It makes sense to bolster the mating component's ability to retain a fastener.

Geek time.

Guitar neck ferrules are intended to be used with countersunk wood screws which normally have something like an 80-82° pitch behind the head. According to ISO 10642 hex head bolts have a larger angle of around 90° which means they might not seat perfectly but near enough as to make no difference.

Button head or low head bolts might provide a visual alternative also, plus these mean you can either add a flat washer or nothing at all since the bearing surface area behind the bolt head is just as large.

Check these out for some variety. I bet they would be great for builds such as your recent crazy blue hardware madness.

http://www.ebay.com.au/bhp/bottle-cage-bolts

[SwedishLuthier]

Hm, strange thing with the pic... here it is: