Calculating Small Format Interchangeable Cores A4 Pinning Stacks - Kaba 5402 Series Technical Manual

Calculating Small Format Interchangeable Cores A4 Pinning Stacks

A4 system has six depths numbered 0 to 5, shallow to deep, respectively. This is a single step progression
system. Because there is no parity in the A4 system, key interchange between systems in the same keyway
cannot be prevented.
The operating and control shear lines are distinct. All the operating keys work at the operating (plug) shear
line. Only the control key works at the control shear line.
Pin to the operating keys first. The shallow cut determines the bottom pin. A master pin makes up the differ-
ence between shallow and deep operating cuts. The numerical value of the bottom pin and master pin
together is called the "plug total." For example, a #1 bottom pin plus a #4 master pin results in a plug total of
5.
Buildup pins are added to the plug total to make the control key operate at the control shear line. Top pins
are added to achieve a uniform pin stack height of 14 in all chambers.
The control dimension, or thickness of the control lug, is a multiple of the increment. The increment is 0.021"
while the control dimension is 0.21". Because the control lug is 6 increment units thick, the control shear line
is 6 units higher than the operating shear line.
Calculating the pin stack
3. Add a top pin to bring the total pin stack to 14.
2. Add 6 to control bitting. Subtract plug total.
The remainder is the buildup pin.
1. Pin operating keys to the plug shear line.
The plug total equals the deep operating bitting.
add top pin to
make a stack
total of 14
buildup pin equals
control cut + 6
minus plug total
master pin equals
the deep operating
cut minus the
shallow cut
plug total
bottom pin
equals the shallow
operating cut
Section 3 - 20