NC Locksmith License Exam Section
2: Pin & Disc Questions and Approved
Solutions 2024
A
VI
TU
Bible - ANSWER that portion of the cylinder shell which normally houses the pin
chambers, especially those of a key-in-knob cylinder or certain rim cylinders
Broach - ANSWER 1. A tool used to cut the keyway into the cylinder plug. 2. To cut
the keyway into a cylinder with a broach
IS
CAM - ANSWER 1. A lock or cylinder component which transfers the rotational
motion of a key or cylinder plug to the bolt works of the lock. 2. The bolt of a cam lock
M
Chamber - ANSWER any cavity in a cylinder plug and or shell which houses the
O
tumblers
Composite Keyway - ANSWER a keyway that has been enlarged to accept more
A
than one key section, often key sections of more than one manufacturer
N
Disc Tumbler - ANSWER 1. A flat tumbler which can be drawn into the cylinder plug
by the proper key so that none of its extremities extends into the shell. 2. A flat usually
rectangular tumbler with a gate which must be aligned with the sidebar by the proper
JP
key. NOTE: sometimes called a wafer tumbler
Graduated Drivers - ANSWER a set of top pins of different lengths. Usage is based
on the height of the rest of the pin stack, in order to achieve a uniform pin stack height
Increment - ANSWER a usually uniform increase or decrease in the successive
depths of a key cut which must be matched by a corresponding change in the tumblers
, Mogul Cylinder - ANSWER a pin tumbler cylinder with a diameter of 2.0", whose
pins, springs, key, etc. may also be proportionally increased in sized, it is frequently
used in prison locks
Mortise Cylinder - ANSWER A threaded cylinder typically used in mortise locks of
American manufacture
Mushroom pin - ANSWER a pin tumbler, usually a top pin, which resembles a
mushroom. It is typically used to increase pick resistance
A
Paracentric - ANSWER Of or pertaining to a keyway with one or more wards on
VI
each side projecting beyond the vertical center line of the keyway
Peanut cylinder - ANSWER a mortise cylinder of 3/4" diameter
TU
Pin chamber - ANSWER the corresponding hole drilled into the cylinder shell and/or
plug to accept pins and springs
IS
Pin stack - ANSWER all the tumblers in a given pin chamber, see also pin stack
height
Pin stack height - ANSWER the measurement of a pin stack, often expressed in
M
units of the lock manufacturers increment or as an actual dimension
O
Plug - ANSWER the part of the cylinder which contains the keyway, with the tumbler
chambers usually corresponding to those in the cylinder shell
A
Plug follower - ANSWER a tool used to allow the removal of the cylinder plug while
retaining the the top pins, springs and/or other components within
N
Plug holder - ANSWER a holding fixture which assist in the loading of tumblers into
a cylinder
JP
Profile cylinder - ANSWER a cylinder with a usually uniform cross section, which
slides into place and usually is held by a mounting screw. It is typically used in mortise
locks made outside of the United States
Retainer - ANSWER a component which is clipped, staked, or driven in place to
maintain the working relationship of the other components
2: Pin & Disc Questions and Approved
Solutions 2024
A
VI
TU
Bible - ANSWER that portion of the cylinder shell which normally houses the pin
chambers, especially those of a key-in-knob cylinder or certain rim cylinders
Broach - ANSWER 1. A tool used to cut the keyway into the cylinder plug. 2. To cut
the keyway into a cylinder with a broach
IS
CAM - ANSWER 1. A lock or cylinder component which transfers the rotational
motion of a key or cylinder plug to the bolt works of the lock. 2. The bolt of a cam lock
M
Chamber - ANSWER any cavity in a cylinder plug and or shell which houses the
O
tumblers
Composite Keyway - ANSWER a keyway that has been enlarged to accept more
A
than one key section, often key sections of more than one manufacturer
N
Disc Tumbler - ANSWER 1. A flat tumbler which can be drawn into the cylinder plug
by the proper key so that none of its extremities extends into the shell. 2. A flat usually
rectangular tumbler with a gate which must be aligned with the sidebar by the proper
JP
key. NOTE: sometimes called a wafer tumbler
Graduated Drivers - ANSWER a set of top pins of different lengths. Usage is based
on the height of the rest of the pin stack, in order to achieve a uniform pin stack height
Increment - ANSWER a usually uniform increase or decrease in the successive
depths of a key cut which must be matched by a corresponding change in the tumblers
, Mogul Cylinder - ANSWER a pin tumbler cylinder with a diameter of 2.0", whose
pins, springs, key, etc. may also be proportionally increased in sized, it is frequently
used in prison locks
Mortise Cylinder - ANSWER A threaded cylinder typically used in mortise locks of
American manufacture
Mushroom pin - ANSWER a pin tumbler, usually a top pin, which resembles a
mushroom. It is typically used to increase pick resistance
A
Paracentric - ANSWER Of or pertaining to a keyway with one or more wards on
VI
each side projecting beyond the vertical center line of the keyway
Peanut cylinder - ANSWER a mortise cylinder of 3/4" diameter
TU
Pin chamber - ANSWER the corresponding hole drilled into the cylinder shell and/or
plug to accept pins and springs
IS
Pin stack - ANSWER all the tumblers in a given pin chamber, see also pin stack
height
Pin stack height - ANSWER the measurement of a pin stack, often expressed in
M
units of the lock manufacturers increment or as an actual dimension
O
Plug - ANSWER the part of the cylinder which contains the keyway, with the tumbler
chambers usually corresponding to those in the cylinder shell
A
Plug follower - ANSWER a tool used to allow the removal of the cylinder plug while
retaining the the top pins, springs and/or other components within
N
Plug holder - ANSWER a holding fixture which assist in the loading of tumblers into
a cylinder
JP
Profile cylinder - ANSWER a cylinder with a usually uniform cross section, which
slides into place and usually is held by a mounting screw. It is typically used in mortise
locks made outside of the United States
Retainer - ANSWER a component which is clipped, staked, or driven in place to
maintain the working relationship of the other components
