regarding to the thickness of the neck at head angle break

Hello! Everyone,
I am following the hana lima plan to construct my current build.
I have a question about the thickness of the neck.
In their concert and tenor plans, they both call for 7/16" (0.4375") for head stock all the way to the 15-degree head angle break, then the thickness gradually increases to 5/8" right in front of the heel.

I followed this to carve two concert necks. But I felt that 0.4375" at the head angle break seems to be too thin. I am afraid that the neck might break at this spot down the road.

These two necks, one is made of spanish cedar, the other is sitka spruce. Scarf joint....and no carbon fiber reinforcement.

I am wondering whether this is something I should be worry about.
Should I increase the thickness around that area next time?
I hope my description makes sense..
Thank you, I really appreciate your thoughts.

My necks are 12mm thick at the nut tapering to 15mm as it transitions into the heel. I use a CF reinforcement down the centre that runs into the head stock. Most times I also add a back graft to the head stock. I can't see for the life of me how one of my necks would break unless it was stepped on. But I don't build with a spruce neck blank.

Those are my dimensions as well. I feel better using a CF rod in my Spanish cedar necks although not for that particular reason. As Allen said, if you're grain is straight, only a freak accident should cause failure there; dropping, stepping on, bar fights, etc. It's nice to know you've got some added protection there with the CF.

I've been looking at a lot of necks lately..I notice that on quite a few including Fender and Martin "on guitars and old Ukes"..the thinnest part of the neck is at the 1st fret "not the nut" ... Is there a reason for this ? you can see it clearly on this cross section photo of a "Taylor guitar neck.
..it's the same on my old Martin soprano, my Fender P bass,and Telecaster.

Timbuck said:

I've been looking at a lot of necks lately..I notice that on quite a few including Fender and Martin "on guitars and old Ukes"..the thinnest part of the neck is at the 1st fret "not the nut" ... Is there a reason for this ? you can see it clearly on this cross section photo of a "Taylor guitar neck.

..it's the same on my old Martin soprano, my Fender P bass,and Telecaster.

Click to expand...

Paying attention to a neck of my own as I was carving it the other day I noticed I had a tendency to do that myself, carving it thinnest at the first fret then graduating both ways from there.

You're supposed to measure the thickness along the neck? hmmm

You gotta be some really big bad ass to take a uke to a bar fight Chuck..

And as does Chuck, I add the CF to the whole neck for other reasons than breakage concerns, but do run in through into the headstock for that as insurance.

I hope this helps someone..It's a detail sketch I made of a 1930's Martin Soprano...It was pointed out to me about the 1st fret thickness by "Dennis Teeth" a noted UK uke player.