All Notches are 22mm wide and 9mm deep.
These are designed for B.S. National
Hives.
The strips are 420mm long, 28mm wide with 1.5mm fixing holes.

I usually drill 3 extra fixing holes as I find that with
only 4... the strips tend to bow between the fixings, due to seasonal
shrinkage and expansion.
The 12's and 13's are used in mating nucs in an attempt to
reduce the possibility of drone production.
The 12's are also used in extra shallow (75mm tall) ekes
with top bars and starter strips... for cut comb (link) production (and
also to satisfy the bees need for comb building).
There is another, shorter style of castellated spacer that
is made in 10's, 9's and 8's spacing to suit the nominally 10 frame
WBC type of hive.
I use 19 mm black parkerised
gimp pins to fix the strips
and I use a spacing jig (future page) to ensure accurate depth of
placement (I use Top Bee Space).
The material used is 28 SWG Zintec coated steel sheet and
they can be purchased from
B.J. Engineering.
Written... Summer 2000, Revised... 29 November 2001
Revised... 28 May 2002