Threaded inserts

SteveF

Any particular recommendations or stuff to watch for with threaded inserts?  I have read advice about sticking to steel rather than brass etc when working with hardwood. 

I am thinking that M5x45mm inserts with M5 x 45mm screws should do the job.  I (think) I am after M5x45 oval headed countersunk machine screws? 

https://www.amazon.co.uk/Threaded-Flanged-Furniture-Carpenter-Project/dp/B09N1Q6V56/ref=sr_1_51?crid=1KN5OVISFJYEF&keywords=steel%2Bthreaded%2Binserts&qid=1701440642&sprefix=steel%2Bthrea%2Caps%2C83&sr=8-51&th=1

https://www.amazon.co.uk/sourcing-map-Phillips-Stainless-Countersunk/dp/B0CCY92WKM/ref=sr_1_3_sspa?crid=2CSI6577DDOOZ&keywords=M6%2Bx%2B45mm%2Bmachine%2Bcountersunk%2Bphillips%2Bscrew&qid=1701441674&sprefix=m6%2Bx%2B45mm%2Bmachine%2Bcountersunk%2Bphillips%2Bscrew%2Caps%2C62&sr=8-3-spons&sp_csd=d2lkZ2V0TmFtZT1zcF9hdGY&th=1

EDIT: for attaching neck to body on a bolt on, if that wasn't clear. 

TTony

I generally use something like this ...


https://graingerguitarparts.com/products/grainger-neck-ferrule-kit-m5-x-35mm


The screws/bolts only need to be as long as the neck is thick, less the depth of the recess plus the length of the insert - 45mm might be too long.

BillDL

You have bought from Reid Timber in the East End of Glasgow before.  They sell the cups and screws or stainless steel bolts, brass inserts, and an appropriately sized drill bit:

https://www.reidtimber.co.uk/inlays-and-fittings/neck-fixing-bolts-screws-and-plates

Just an example.  Loads of other places do them.

As far as brass vs steel inserts goes, my feeling is that the neck doesn't need to be tightened enough whereby there would be a risk of the steel bolts stripping the softer brass inserts.  I suppose if you had the neck on and off a guitar a great many times, then the thread in the brass inserts might start wearing, but realistically I don't think there would be an issue.

SteveF

I was more worried about rounding/breaking the insert trying to fight the outer threads through hard maple, but good to know that's not an issue.  The Reid kits look to be about what I am looking at on Amazon.  I had found this image online which is what I was going off for the length - I think 40/45 might be for when you are not recessing them in the ferrule and have the extra neckplate thickness: 



I suspect they would be too long with the neck ferrules. My main concern was whether brass would be ok. But sounds like it should be fine too  

Roland

Definitely M5 for necks. Like @TTony I prefer countersunk hex bolts instead of slot or cross head screws. A screwdriver can raise a sharp burr on a screw head, whereas an Allen key doesn’t. I know you can buy bolt, ferrule, and insert separately. However the last couple of times I’ve bought a set of four from Grainger because I’m buying their knobs and other parts at the same time. 

BillDL

I've only ever built, or rather modded and assembled, one guitar with the bolt and threaded insert fixings.  It was a maple neck and the brass inserts bit their way into the maple fine without getting tight enough to worry me that the hex socket might start getting chewed up and rounded, or that they may break.  I suppose if you drilled a hole that was too small that might happen though.  I see no reason why you couldn't use steel ones as opposed to brass though.  If I was to do this again I would definitely choose the bolts with the hex socket as recommended by Roland.

FelineGuitars

I use both M4 and M5 versions 

Typically M5 if using the countersunk ferrules but on some Fender like neck plates you have to use an M4 to get a screw head that won't spill out of the countersunk plate

Gizmo

I used "Weld Tee Nuts" M6 on my last neck for a Vader type headless build & they were great.

Of course these only work if you are building your own Neck/Fingerboard and get to them inserted/pocket before you put the fingerboard on,i pined/CA'ed these inplace as well as them being inset in pockets so they couldn't twist.