“It's nice to know that
I have a good
source for quality
guitar wood as
well as guitar parts
fabrication, such as
LMI's fingerboard
slotting service. 
As I am only set up
to slot 650mm
fingerboards, you
guys have saved my
butt on making me
several odd scale
lengths recently! 
I want you to know
that I appreciate
you guys and the
wood and services
that you supply
to me, a small,
independent luthier. 
Your fine fingerboard
slotting service
saves me a lot of
time and trouble,
for which I am grateful. 

Bob Desmond

Neck Joint Jig and Templates

  SPMTKS/SPMTKD O'Brien neck joint jig

  SPMTKS/SPMTKD O'Brien neck joint jig 
and SPMTS template.

  SPMTS straight mortis & tenon template
  SPMTD, dovetail mortis & tenon template

Robbie O'Brien has designed this easy to use neck joint jig to determine your neck angle and then route either a dovetail or straight mortise and tenon neck joint. This jig kit comes with all the assembly hardware, a straight or dovetail mortise and tenon template set (your choice), and a 5 page CAD plan – all you supply is the wood!

The video/article links (below) fully illustrate how to assemble/use the jig and have many helpful hints for making easy work of this often difficult task.

The LMI mortise and tenon templates (SPMTS, SPMTD) are designed to be used with the O'Brien Neck Joint Jig, but they can also be used separately. They are manufactured from 1/4 inch mdf to keep the price reasonable. If you expect to use these templates more than a few times in your shop, we recommend flooding the adjustment slots with cyano-acrylate glue to harden them a bit and prolong the life of the jig.

You need to use a 5/8 inch OD router guide bushing when using these templates. Sets of guide bushings can typically be purchased wherever routers are sold.  Our 3/8 inch bit (SPRB38) works well for hogging out the material on a dovetail–then you can follow with the 7 degree dovetail bit (SP7DT). Use the 1/2 inch straight bit (SPRB12) for use with the straight mortise and tenon template.

Router bits are not included with the kit.

The dimensions of the mortise and tenon prior to fitting them are:

  • Mortise - 7/8" (.875")
  • Tenon - 15/16" (.938") The tenon is slightly oversized so you can remove just a bit of material and get a perfect fit.

PLEASE NOTE: The dovetail mortise and tenon templates are different lengths to accommodate the offset created by the template guide when routing the dovetail mortise.



SKU Product Name In Stock Each  
SPMTKS Jig, neck Angle/Mortise and Tenon, straight
Yes $121.75
SPMTKD Jig, Neck Angle/Mortise and Tenon, dovetail
Yes $121.75
SPMTS Template, LMI mortise & tenon, straight
Yes $31.45
SPMTD Template, LMI mortise & tenon, dovetail
Yes $31.45
SPRB38 Neck joint router bit, carbide straight cut, 3/8" cutter, 1 1/4" LOC, 1/2" shank, 3" OAL
Yes $16.85
SP7DT Neck joint router bit, carbide 7° dovetail, 1/2" cutter, 3/4" LOC, 1/2" shank, 2-1/2" OAL
Yes $22.84
SPRB12 Neck joint router bit, carbide straight cut, 1/2" cutter, 1 1/4" LOC, 1/2" shank, 3" OAL
Yes $18.85