Neck Screw Torque

Molochnik · #1 03-18-2011, 06:15 AM

I tried a couple of searches, but they didn't seem to turn up anything specific.............
I'm curious if anyone uses a torque wrench/screwdriver and/or a particular torque setting when installing neck screws back into wood that's in good shape. I build motorcycle engines and am generally very anal about torqueing everything that I can find a value for, or reasonably guess at (standard torques of similar models) if no tech data exists. I generally don't work with wood; certainly not anything serious/important, but I think basses (mine anyway

) are about to become part of my maintenance repertoire.

The particular instrument I intend to remove the neck plate from is my new Epi T-Bird Goth, if that makes any difference.

Thanks in advance for any guidance.

JB696 · #2 03-18-2011, 09:26 AM

Install the screws dry, no wax or lube, and tighten them until they squeak once. If the corners of the neck plate aren't bent down, one more squeak, then stop. Sorry, just kidding. The standard Fender design is defective because they use a soft, thin neck plate with not enough edge margin around the screws. As a result the corners will always bend down. I see warped plates on most new Fenders and on all used ones where the neck has been removed and re-installed a few times. Fortunately, the Epiphone plate is a much better design so you won't have to worry about warpage like on the cheap, defective Fender ones. I don't have a torque figure, but if the neck wood and threads are in good shape I'd tighten them about as tight as I would some #10x32 screws into the aluminum threads of an engine case, like on a side cover. Except without the Loctite. I'm sure somebody can give you an actual inch pound figure so check back later.

mongo2 · #3 03-18-2011, 09:57 AM

Never heard of anyone actually using a torque wrench to tighten standard neck screws.

Rickett Customs · #4 03-18-2011, 10:02 AM

It would take a greasemonkey to think this way, j/k

It could be done, but it's one new step that I won't adopt, don't want no more extra steps

stflbn · #5 03-18-2011, 10:03 AM

Torque wrench number won't work because it's all dependent on the wood that the screw is screwing into.

General answer... the screws can be screwed in as tight as they can be without stripping, but really... the neck only needs good solid contact with the body.

Molochnik · #6 03-18-2011, 10:33 AM

@ stflbn & mongo2 - I suspected wood type might make a single rule impossible, and unfortunately cranking 'em down 'til they strip is more than likely the standard procedure. I guess that's why I came across so many threads on repairing worn out/stripped screw holes, and nothing on torque values (hmm, smilies aren't working - this is all tongue in cheek!)

@ Rickett - Very astute comment; I've got "Grease Monkey" tattooed on my forearm!

@ JB696 - I like the idea of ~7 to 9 ft/lbs like a case or side cover.

No doubt, there are many who have a good feel for wood and see the use of a torque wrench as superfluous for good reason. I just like the affirmation of knowing for sure that if something goes wrong, it wasn't due to my error. I guess if worse comes to worse, a set of inserts will get me back to a metal-metal deal where I'm most comfortable.

Thanks!

grisezd · #7 03-18-2011, 10:38 AM

I've never seen torque specs for threads into wood, but if you do go to inserts you can probably get max torque figures on those, then use the lower of the standard torque spec for the fastener or the insert.

I think I would go to contact, then to what feels "firm", then another quarter turn or so.

Rickett Customs · #8 03-18-2011, 10:41 AM

I'll rephrase, It will work....but, no 2 will be exactly similar (different wood species act different, concerning screws...think a softer wood and a denser wood)). Especiallly, ones that are screw to wood, or machine bolt to threaded inserts......

mongo2 · #9 03-18-2011, 10:42 AM

Quote:

Originally Posted by Molochnik

No doubt, there are many who have a good feel for wood and see the use of a torque wrench as superfluous for good reason. I just like the affirmation of knowing for sure that if something goes wrong, it wasn't due to my error.

Well, it's not like the bass will spring a leak of the neck screws aren't torqued enough.

I've used threaded inserts and machine screws several times. I feel more confident in tightening the machine screws more than the wood screws but in general I found it didn't make much difference. Tight enough is apparently tight enough.

Next thing you know somebody is going to put up some sort of bogus test of neck screw torque to see if anyone can tell the difference through several thousand miles of internet and satellite skips.

ia02 · #10 03-18-2011, 10:43 AM

I think a torque wrench would create more errors than it saved. Wood is not metal, and, in my opinion wood requires a bit more finesse. That being said, maple is hard and can take a serious amount of torque. A quality wood screw in maple should handle as much torque as a similarly sized machine bolt into a typical automotive application (like a cast engine block).

Then again metal isn't always perfect either. I'm sure you've experienced soft metals like cast aluminum stripping way before proper torque specs are reached.

stflbn · #11 03-18-2011, 10:44 AM

Inserts are great, but also can allow a person to be 'to' aggressive. I cracked the finish around the neck plate by tightening to much at the builders suggestion that tightening further could help with a neck dead spot.

Wasn't horrible, or that noticable, but it definitely had 'contact'. (Didn't help with the dead spot btw.)

walterw · #12 03-18-2011, 11:36 AM

they should be as tight as they will go without bending that thin fender neck plate.

any more and you're just crushing wood.

more important is to make sure they're slipping through the body and only threading into the neck. (obvious, i know, but i see too many supposedly good guitars where this is not the case!)

Molochnik · #13 03-18-2011, 11:46 AM

Thanks for all the good advice! I'm actually going to fabricate my own neck plate that will also provide a strap attach point.........in fact it'll probably turn out to be a couple of different neck plates as I fiddle w/ a couple different designs to solve the balance issues that T-birds are so notorious for. The portion where the neck screws will go through will likely be somewhere around .250 thick so I would expect the wood to give out before the neck plate. I never noticed how the thickness of the Fender plates is lacking, but it is this Epi I've been most preoccupied with "fixing".

walterw · #14 03-18-2011, 03:38 PM

if that epi has a mahogany neck, be careful, as that's a softer wood than the typical fender maple.

i often see people mod the upper-most neck screw to hold a strap button to try and get that strap a little more forward.

are you thinking of something where the neckplate itself has some sort of protruding flange with the button on the end?

Molochnik · #15 03-18-2011, 03:59 PM

Yes..........I also figured it would be better to spread the weight of the bass over all 4 screws as well. But yes, I was going to extend it out - down the neck while trying not have anything "weird" looking. If I can get the point of contact right, I'm hoping to have it "lay" properly so I don't have to hold it in position and/or rock it forward or back for comfortable fretting.
I bought some strap locks and it looks like there's too much distance between the starp and where the lock actually screws into the body; a lot of leverage in the wrong direction. I figure if I can just use a robust bolt to deal with the cantilevered load, the threads in the wood would have to take such a beating. If the strap buttons/locks aren't being over-tightened, I suspect that this has much to do with chronic problems concerning strap fastener holes.
I realize I'll have to keep it out of the way for getting to the upper frets too.
I'm sure someone has probably tried this, but I'm kind of a geek about solving problems like this..........plus it appears that it will be much easier on my wallet than bike customization/performance. I need some outlet.

Molochnik · #16 03-18-2011, 04:04 PM

Sorry, it should read " I figure if I can just use a robust bolt to deal with the cantilevered load, the threads in the wood would NOT have to take such a beating."

I've been having some issues with this site: not all the buttons show up, smilies don't work, no option to edit posts, etc.

loinmute · #17 03-18-2011, 06:12 PM

Quote:

Originally Posted by walterw

they should be as tight as they will go without bending that thin fender neck plate.

any more and you're just crushing wood.

more important is to make sure they're slipping through the body and only threading into the neck. (obvious, i know, but i see too many supposedly good guitars where this is not the case!)

I thought you wanted threads in the body too?

OOZMAN · #18 03-18-2011, 06:24 PM

If you were a mechanic then you should have a 'feel' for how tight a screw can/should go. Even if it is wood.

peace

Molochnik · #19 03-18-2011, 06:38 PM

Quote:

Originally Posted by OOZMAN

If you were a mechanic then you should have a 'feel' for how tight a screw can/should go. Even if it is wood.

peace

I disagree........torqueing fasteners is not necessarily about feel. I repair plenty of threads stripped out by mechanics.

Molochnik · #20 03-18-2011, 06:43 PM

Quote:

Originally Posted by loinmute

I thought you wanted threads in the body too?

The neck would not be drawn to the body as tightly if both the body and neck were threaded.

I suspect this happens as a manufacturing shortcut - match-piloting both holes and then zipping the screws in.........but I don't know anything about guitar factories.