What Size Allen Key?

BigPaulie

https://www.amazon.co.uk/dp/B007JXASE4/ref=cm_sw_r_apan_glt_i_RHQ9G2KSWBT9GR50PGN2

Mellish

@BigPaulie ; yep, then slide a bit of tube over the short end as ICBM said. Or you can get ones that have a much longer "short" end  

BigPaulie

I just grab the short end with a pair of pliers or the ring end of a spanner. There's always many many more than one way to skin a cat.

DLM

BigPaulie said:

https://www.amazon.co.uk/dp/B007JXASE4/ref=cm_sw_r_apan_glt_i_RHQ9G2KSWBT9GR50PGN2

If access to the OP's bolt head is so far from the access point that he'll need the long end of the allen key, I'd strongly advise him against trying to put any sort of torque on with a ball-ended allen head!

I've a fairly inexpensive bit/socket set with all kinds of options to make any hard-to-reach fasteners loads easier to tighten/loosen.

This sort of thing: https://m.media-amazon.com/images/I/71wKlZIPLUL._AC_SL1001_.jpg

BigPaulie

You shouldn't need much torque to turn a truss rod.
And although I can't speak to that particular set of keys, I have put 25Nm on a 4mm ball end in the last week. No damage to key or bolt head.

Jimbro66

I use one of these from Axminster tools:

https://www.axminstertools.com/proxxon-l-handle-hex-screwdriver-hex-4mm-953142

They come in a range of sizes.

It makes adjusting the truss rod of my Atkin a doddle compared to fiddling about with the small Allen keys in a typical set.

DLM

@BigPaulie No, ideally not, though my guitars have always seemed to stick a little before they'd turn and no one wants to round out the bolt head. Quality keys make a big difference, of course. I bit the bullet and got a full set of Wiha's several years back, but I'd always bought at least servicable ones (singly, if strapped for cash) on my dad's advice.

guitarjack66

DLM said:

BigPaulie said:

https://www.amazon.co.uk/dp/B007JXASE4/ref=cm_sw_r_apan_glt_i_RHQ9G2KSWBT9GR50PGN2

If access to the OP's bolt head is so far from the access point that he'll need the long end of the allen key, I'd strongly advise him against trying to put any sort of torque on with a ball-ended allen head!

I've a fairly inexpensive bit/socket set with all kinds of options to make any hard-to-reach fasteners loads easier to tighten/loosen.

This sort of thing: https://m.media-amazon.com/images/I/71wKlZIPLUL._AC_SL1001_.jpg

I've actually got a set of these which I never even dreamed of using for a guitar!

Tannin

Yep. One size fits all. Yesterday I had a couple of gins for breakfast, put new strings on the Subaru, and changed the oil on the Maton. What could possibly go wrong?

BigPaulie

guitarjack66 said:

DLM said:

BigPaulie said:

https://www.amazon.co.uk/dp/B007JXASE4/ref=cm_sw_r_apan_glt_i_RHQ9G2KSWBT9GR50PGN2

If access to the OP's bolt head is so far from the access point that he'll need the long end of the allen key, I'd strongly advise him against trying to put any sort of torque on with a ball-ended allen head!

I've a fairly inexpensive bit/socket set with all kinds of options to make any hard-to-reach fasteners loads easier to tighten/loosen.

This sort of thing: https://m.media-amazon.com/images/I/71wKlZIPLUL._AC_SL1001_.jpg

I've actually got a set of these which I never even dreamed of using for a guitar!

Why ever not? An Allen key is an Allen key.

If you're worried about using the ball end buy Draper 33576 (4mm extra long) and 33577 (5mm extra long).

I would be 100% confident in using the ball end of the tool I linked above, but I have years of experience using similar tools (although not that particular one) in much more demanding applications (bicycle, car and small engine repair) than guitar truss rods.

EDIT: I thought OP said he already had a set of ball ended keys; not the kit linked by DLM

ICBM

guitarjack66 said:

I've actually got a set of these which I never even dreamed of using for a guitar!

Don't use those. For one, there *is* a risk of putting too much torque on - it's usually not a hazard at all with a pure hand tool, but that ratchet handle or even the smaller tommy bar might do - but more importantly, the couplers between the extension sections are probably too large to fit through the hole in the top braces... or worse, are *just* small enough to fit through but snag on the way out and leave the last piece trapped in the guitar.

You need a proper long Allen key if a standard one won't reach the 'wrong' way round. I actually wonder if Martin do this on purpose to make it harder to reach without their own proper tool. The new Fender Paramount acoustics are even more so, the Allen socket is right in the neck heel, several inches from the soundhole - although they do supply the correct tool as well.

Mellish

Be careful that you don't use the truss rod to adjust the action. It's a trap some fall into. I'm sure you know what the truss rod is for, just saying  

DLM

T'is a fair point. A lad I went to school with actually thought he could adjust the fingerboard radius with the trussrod. Oops.

Mellish

DLM said:

T'is a fair point. A lad I went to school with actually thought he could adjust the fingerboard radius with the trussrod. Oops.

You'd be surprised. I'm sure techs could tell some horror stories  

ICBM

DLM said:

T'is a fair point. A lad I went to school with actually thought he could adjust the fingerboard radius with the trussrod. Oops.

You can adjust the fingerboard radius on a vintage Rickenbacker with the truss rod if you're not careful.

Very oops...

DLM

Quite. This was a Yamaha RGX121D, FWIW. I took it to a gig as a backup guitar once, and was very glad I had as I broke a string.