Calculating Small Format Interchangeable Cores - A2 System Pin Stacks - Kaba 5402 Series Technical Manual

Calculating Small Format Interchangeable Core – A2 System Pin Stacks
A2 system has ten depths numbered 0 to 9, shallow to deep, respectively. Two step progression must be
used to prevent key interchange. In A2 system, parity must be maintained in each position, i.e., only the odd
or even cuts may be used in a given pin chamber.
When a key system is written, the choice of a TMK automatically determines the parity pattern. Section 4 of
this Manual has forms with all sixty-four parity patterns to use in maintaining a TMK register. This can also
be done with a computer and data base program.
The operating and control shear lines are distinct in all positions. All the operating keys work at the plug
(operating) 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
difference 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 #3 bottom pin plus a #4 master pin results in a plug
total of 7.
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 23 in all chambers.
Calculating the pin stack
3. Add a top pin to bring the total pin stack to 23.
2. Add 10 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.
Section 3 - 17
add top pin to
make stack total 23
buildup pin equals
control cut + 10
minus plug total
master pin equals
the larger of the
master key or oper-
ating key cut minus
the bottom pin
bottom pin equals
plug total
the smaller of the
master key or oper-
ating key cuts