Hardware Function Choices and Lockdown Procedures
K-12 and University Classrooms
Jim Harper, CRL, CIL K-12 and university specialist, ASSA ABLOY
Introduction
Historically, schools used a single-sided classroom function lock on doors leading into classrooms. This function allowed the first person in to insert their key, rotate it 360°, and put the lockset into “passage function” or unlocked for the day. During a lockdown, the staff had to open the door, then insert their key to lock the door, putting them at risk.
Some schools would use an office function lock, which has a turn button on the inside that can lock or unlock the outer trim. The difficulty with this is that students can lock the door as a prank. The school could also have a liability issue with this function if one student forces another into the room, locks the door, and does harm to the other person.
Another option is using a storeroom function lock, which is always locked and the door is left open all day. This would require teachers to carry their classroom key with them at all times and lead to interruptions every time someone wants to come in when the door is closed. In larger schools with multiple classroom keys (keyed to departments), the teacher could be in an area where their key does not allow access to the classrooms they want to bring students into as a place of safe haven, thus leaving them exposed.
The classroom intruder function lock acts as the traditional classroom function lock but has a keyed cylinder on the inside that locks the outside trim. In a lockdown, the staff uses their lockdown key on the inside to lock the door without exposing themselves to potential harm. Teachers in any part of the building can go into any unlocked room and use this key to secure the room.
Any brand names mentioned in this chapter should not be considered endorsements, but rather suggestions from the author’s own experience of products that have proven to be high quality.
Theoretical Discussion on Classroom Intruder Function: Keying Options
Exterior-Side Keying
There are several different ways of keying the inside cylinder on the intruder function lock, and in my experience, the level of school (K-6, middle school, and high school) changes the way these locks are keyed. When consulting with a school about safety, I will discuss in depth the various options with the school administration or superintendent and let them make the decision of which option best suits their operational and lockdown procedures.
In the K-6 elementary school setup, the teachers generally stay in their assigned rooms. In most cases, the classrooms are all keyed alike (e.g., exterior / hallway side). You need to ask if the classrooms are ever really locked by the staff during the day or only secured at night by the custodians for after-hours security reasons. You should also ask if teaching staff need to carry an exterior side classroom key. Suggestion: Use a second combination for all interior lockdown cylinders and require staff to carry this key at all times. The reason for using a second combination is that this lockdown key does not unlock locks from the hallway side; rather, it only locks doors from the inside of the classroom. A second combination would prevent an intruder from taking keys away from a staff hostage to gain entry into secured rooms.
In the middle and high school environments, the teachers do move around to various classrooms. Therefore, in middle schools, there may be a need for several different keys: a common general classroom key, an art key, a gym key, a music key, and so on. In high schools and university settings, there may be a need to key by department and there may be up to 20 different department masters. Further, under these there could be a common department classroom key, a department head admin office key, a department storage key, or a computer lab key.
Interior-Side Keying
The physical layout of the building may affect the keying, such as keying all classrooms by building wings rather than by class discipline. Each school is different in layout and department structure and operational policy.
Since the shooting at Virginia Tech, I recommend that the lockdown key be a separate combination and that all school personnel (teachers, aides, custodians, administrators, nurses, food services personnel, etc.) carry this key with them at all times. Schools will need to consider their policy on sign-out keys for substitute teachers and staff that travel between schools such as PE or special education teachers. Ideally, the teachers will carry two keys: a regular exterior-side classroom key (which can be kept in their pocket or in their desk) and the lockdown key, which must be on their person at all times. Some school districts will purchase lariats for this key (and ID card) to be worn at all times. In this case, I will key the teacher lounges, copy rooms, and rest rooms to this key to force teachers to carry the lockdown key with them at all times. Under this concept this key only operates the inside lockdown cylinder. Therefore, if a perpetrator does incapacitate or take a staff member hostage, this key will not unlock the doors from the exterior side. As part of the lockdown procedures, the school could inform students as to how this key works so they could take the key from an incapacitated teacher and go into an unlocked room and lock themselves in.
In some cases where the school administration does not want the teachers to carry two keys, I have cross-keyed the inside cylinder to be operated by all classroom keys. Under this concept, there is no lockdown key and the teaching staff must take steps to protect their keys. This allows any teacher to enter any unlocked classroom during a lockdown and be able to close any of these doors and lock them with their key from the inside.
In this scenario, the place of exposure now becomes the connecting doors. In most schools, classrooms are left unlocked during operating hours. If a perpetrator gains access into the school, he or she could go into an unlocked classroom and gain access into other rooms through the connecting doors. These doors now need to be viewed as part of the lockdown procedure and a decision made on how to secure them during a lockdown. These doors are not required by code as a secondary means of egress unless the room is designed for more than 50 students, or under NFPA 101, if on a second or third floor there is a designated fire escape window, the door(s) leading to this escape cannot be locked. One option on these is using double-sided deadbolts keyed to the lockdown key only on both sides (the 10G26 function). Again, a policy needs to be established and the local authorities (fire and police) need to be brought in to confer.
This brings up a point on exterior door keying: Ensure that each side of the building(s) has an access point for emergency responders and that there is a policy in place for getting keys to them (for example: Knox boxes, keys in cruisers, or at predetermined locations).
An in-depth discussion with the local authority having jurisdiction, school department administration, school facilities management, and local fire and police representatives should be held before the final design stage of the project. In addition, an in-depth discussion on patented keys should be started in these conversations to educate the end user so they can make an informed decision on the type of key system to use.
Points to Consider on Hardware/Function
Some lock companies offer several different options with the intruder function. Discussion with the end user in preplanning is critical to get the desired operation and level of protection (such as latch only, deadbolt, key operation, etc.). The intruder function is also available on some companies’ exit devices. These can be used for places of assembly, such as the library, gym, auditorium, and multipurpose rooms. However, this does mean that mullions will be needed on each pair of doors so that ADA opening requirements are maintained. The lockdown cylinder is used on the inside of these just as in a classroom.
All exterior exit devices should use a cylinder dogging so that only authorized staff can leave these doors in the unlocked position. All exterior doors should have door-propped-open alarms (alarms that will sound when a door has been propped open) that alert a central manned location, as well as an established response policy.
Cross-corridor doors with exits need to be reviewed when these are to be used to lock off an area after hours while school events are going on and the building is occupied. Again, it is a good idea to use cylinder dogging so that only authorized staff can leave the doors in the unlocked position.
Staff restrooms or workrooms are another area where it is important to have a discussion with the end user in the predesign stage in order to ascertain the desired function. They should be secured to reduce risk of vandalism. Some options include hotel function, occupancy indicators, and combination locks (Sargent KP mortice is recommended). If using a lockdown key, these should be keyed to it to force staff to carry the key with them at all times.
Some newer locks come with an antimicrobial finish. This option should be reviewed with the school district as an added feature to increase student health. This feature is even available for the surface on some thermal fused wood doors.
Pros and Cons of Office Function Locks
Pros
The classroom can be left unlocked during operating hours so students do not interrupt the classroom when returning during classroom time.
Cons
The door could be locked by students, thus locking staff out.
If multiple department keys are used, there is the possibility of a scenario where a staff person is escorting students to other areas in the building during a lockdown and find themselves in a corridor where all doors are locked and their key does not allow access into the classrooms.
Pros and Cons of Storeroom Function
Pros
Classroom doors are always locked.
Cons
Locked doors become a distraction during class when students return to the room, as someone has to allow them in, disturbing the class. Over time, staff will block doors open, or tape latches or strike plates to avoid the class disturbance, thus defeating the purpose of the locked doors.
All staff have to carry their keys with them. In a hostage situation, their key would allow access to some classrooms. However, if, for example, in an elementary school all doors are keyed alike, then all classrooms become vulnerable.
Classroom Intruder Function
This lock acts as the traditional classroom function, but has a keyed cylinder on the inside that locks the outside trim. During a lockdown the staff uses their lockdown key on the inside to lock the door without exposing themselves to potential harm. Teachers in any part of the building can go into any unlocked room and use this key to secure the room. It is recommended that this lockdown key is the same on all doors in the school or district.
The culture change that is required with this function is that all staff must carry the lockdown key with them at all times. In a hostage situation, this key does NOT unlock doors from the corridor side.
Electronic Lock Functions
Various options of electronic locks are available, from stand-alone battery locks to hard-wired and wireless versions.
Each has its own capabilities depending on software options. Stand-alone locks require yearly battery changes. Initial costs would be higher than for mechanical locks and the school would need to require staff to carry access credentials at all times. One should also consider the administrative time required to maintain the software.
When upgrading to new lever-style classroom security function locksets, you will receive an extra benefit of being in compliance with the ADA, which states that door locks must be operable with a closed fist (Figure 18.1).
New classroom security function
Being able to lock the door from the inside during a lockdown avoids exposure of staff to physical risks. Conventional classroom function locks require you to lock the door from the corridor side, which could expose the teacher or student to potential physical risk.
Several well-known lock companies (e.g., Sargent, Corbin Russwin, and Yale) have provided a solution to this dilemma with their classroom intruder function locks available in cylindrical and mortise applications. For some of the devices this helps to alleviate a panic situation where the person may actually unlock the door in the heat of the moment. This function is also available for some exit devices so that areas of assembly such as cafeterias, auditoriums, and gymnasiums can be secured in a lockdown situation by authorized staff.
School Security Door Hardware Upgrade Project
Step 1: What do You Have Already?
You have to conduct a physical inventory or survey of all your facilities. At the same time, start reviewing your philosophy on security and procedures. Doors, frames, door hardware, locking devices, and access control systems should all be looked at as components of your physical security system. Each part plays an important role in providing barriers to unauthorized access to your facilities. A well-designed security philosophy will provide protection of students, staff, and assets and reduce your liability.
Physical locking devices
As stated above, take inventory of what you have for existing hardware products, including product brands and product types per school (this is a simple survey). Older schools may still have knob-style handles, so updating these to newer lever styles will comply with ADA regulations.
A door-by-door survey is a listing of the locking hardware on every door opening in every school. This survey is necessary because once completed you will have a list of the exact quantities of what materials will be needed to upgrade each school. These figures will be helpful in other ways as well. They will be used to process bids for the project. They will be used by the installers to verify that correct hardware is installed on the proper opening. After the installation, they will become a time management (time saving) tool on future service requests and can be used to conduct preventative maintenance schedules.
Once you have completed the survey, determine if a particular brand is the most predominant one in use in your schools. The Builders Hardware Manufacturers Association (BHMA) evaluates and grades commercial hardware. Determine if the hardware used in your school is evaluated and graded by the BHMA. Then evaluate commercial BHMA-certified grade 1 products on the market and establish a hardware standard for your school system. Creating a standard for door hardware will help reduce future operating costs by reducing multiple product inventories, and allow staff to become familiar with maintenance and repairs for just one system, thus reducing labor costs.
Master key system(s)
While you are surveying your school’s hardware, ask the following questions:
1. How many different master key systems are in use?
2. How old are they?
3. What level of key control is in place?
4. Are there records for who has keys to school property?
5. Do any of these systems offer protection against unauthorized duplication?
Master keying gives you the convenience of carrying fewer keys to operate your facilities. It also allows you to segment access to individuals to areas where they need access. This allows a better sense of controlling access but does not offer time zones or auditing capabilities that newer electronic access control devices offer.
Mechanical key systems offer several different levels of protection for you from unauthorized duplication. Plain old conventional keys can be easily duplicated without your authorization. There are “restricted” key sections in which the manufacturers restrict use by geographical boundaries, but key blanks could be made by other companies once economically feasible. There are high-security systems which offer the benefit of patent protection. The highest level of protection is with products that hold a utility patent.
You also have to decide what physical type of product you want to use: conventional, interchangeable, or removable core. These products all have different price points, which will affect the cost of the project. An interchangeable or removable core product has higher initial costs but offers future labor savings when rekeying is required.
During the time the survey is being done you have to create a conceptual schematic of how you want the new master key system designed. There must be a completed design by the time an order for a product is entered.
Access control
Are there any access control systems in use? If so, are they expandable? Are there any intercom or cameras systems in use? New standalone or wireless products will greatly reduce your initial product and installation costs.
You need to establish a plan of action on the implementation of an access control system. Card access systems offer many levels of protection not obtainable with mechanical keys. Access control systems allow you to establish time zones, which assign times of operation for individual cardholders. These systems also provide you with the benefit of reporting when an individual tried to or gained access to your facilities.
The door hardware industry is exploding with new types of products which work with traditional systems or are their own access systems. Newer standalone systems may make more sense in a multiple school system and be less expensive than traditional hard-wired systems. In the near future, wireless products will allow end users all the features and benefits of traditional hard-wired systems at a substantially lower investment. Lay the ground work now for a system-wide access control system (e.g., have teachers who historically possessed keys for exterior doors issued ID cards and channeled into using a single point staff entry door).
Step 2: What Do You Want to Get?
Once the survey is completed you will have an idea of what type of hardware you are using. Now is the time to identify what you want for the future. Usually the most pressing issues are to upgrade older worn-out hardware, replace out of control master key systems, and start an expandable access control system.
In identifying what you want for the future, list what you want to achieve; some examples follow.
Classrooms, gyms, libraries, multipurpose rooms, cafeterias, and auditoriums
For these areas, provide locking capability from the interior side. This is so that during a lockdown condition school staff can secure their areas from the inside of doors without having to expose themselves by opening the door to secure it.
Exterior doors
For exterior doors, you may want a locked trim, interior side locked by a key cylinder dog so that students cannot leave doors unlatched by using an Allen wrench. Use local door alarms to indicate doors that have been propped open so school staff can investigate. Upgrade older style crossbar-type exits with newer rail-style units to prevent doors from being chained closed from the interior side. Reduce exterior doors with pulls that can be chained or otherwise secured from the exterior side.
Key system(s)
Only patented systems that offer a higher degree of protection from unauthorized key duplication should be used. You may want a new single district-wide patented master key system to regain key control on all school buildings. Establish a district policy on key control policy which will outline the in-house procedures to issue, track, and retrieve keys. Establish procedures for requesting keys, serially stamping of keys, key agreement forms, issuing and tracking keys. This policy should:
• Identify the key system administrator;
• Set guidelines on issuing keys by operational need and not convenience;
• Set procedures on tracking all keys;
• Set disciplinary actions for violations of the policy; and
• Set collection of keys, and yearly audits of all keys.
(See Appendix A for a sample employee key request form and sign-out sheet.)
Access control
Identify exterior door controls. You may want a main entry intercom system(s) with remote door release. Consider establishing staff entry points using card access; also establish procedures for delivery of foodstuffs and other vendors. Identify areas that are opened to the public for functions and then create barriers to the rest of the school. Focus on products that require less maintenance and offer low lifecycle operating costs.
Step 3: How Do You Get There?
After the completion of surveys and designing the systems you want to implement, you then need to request costs from vendors. Then you need to decide upon the scope of work to be done and establish budgets and timelines.
Some work can be done in house, some by contractors on bids. Funding may come from yearly maintenance budgets or have to be assigned to capital budgets. You may have to develop a capital improvement project budget with monies designated over several years. There are funds available from federal programs (e.g., Homeland Security) as well as state grants for upgrading school security.
Step 4: Maintain Systems
Most importantly, establish an in-house product guide spec to be maintained and issued for use on new construction and renovation projects to keep continuity of products and services. Educate all staff, including maintenance, new construction planning, and facilities management as to the importance and cost savings incurred by adhering to these standards.
Once you start an upgrade project there is one other critical component to establish. You need to view doors, frames, door hardware, locksets, master key systems, and access control systems all together as one workable system. Historically these components are viewed independently of each other, but they all need to be given the same priority and maintenance attention as your other systems, such as HVAC and fire detection systems. You need to establish yearly maintenance procedures and budgets to properly maintain all these components. Doors, frames, fire door assemblies, locks, and keys all are part of your life safety and security systems. They all require regular inspection and attention to insure they offer you the degree of functionality they were originally designed for.
Conclusion
To aid the reader’s understanding of the terminology used in this chapter, I have attached a set of definitions (Appendix B).2
Appendix A Sample Employee Key Request Form and Sign-Out Sheet
North Crockett Public Schools1
John Wood Administration Building
6 Morse Street
North Crockett, Massachusetts 02760
Employee Key Request Form
| Name (please print): | |||
| Work Phone Number: | |||
| Request for Area/Office(s): | |||
| Key Requested: | |||
| Key Set # : | Serial # | Key Set # : | Serial # |
| Key Set # : | Serial # | Key Set # : | Serial # |
| Key Set # : | Serial # | Key Set # : | Serial # |
| Key Set # : | Serial # | Key Set # : | Serial # |
 Statement of Intent Access control devices for North Crockett Public Schools are controlled by mechanical and electronic locking systems designed at considerable costs to the facility. All combinations for these systems are controlled by the Director of Facilities and Grounds, and are structured for the convenience of employees and departments and for the purpose of maintaining departmental physical security. | |||
| Policy Unauthorized duplication or distribution of a key, access card or access code is strictly prohibited by the North Crockett Public Schools. Any employee who duplicates, alters, or divulges any key, access card, or access code to another person or organization without first receiving the necessary authorization from the Director of Facilities and Grounds may be held financially responsible for any expenses incurred by the North Crockett Public Schools as a result of such disclosure or duplication. In addition, the employee may be subject to discipline up to and including termination for such actions. | |||
| Financial Responsibility The cost of rekeying or combination changes due to a loss or unauthorized distribution of combinations shall be borne by the department authorizing the issuance of said key(s), access cards, or access codes. North Crockett Public Schools will determine whether and under what circumstances all or part of these costs will be passed to an individual department member who has lost or made unauthorized distribution of key(s), access cards, or access codes. Determination of the requirement to re-key or change accesses cards or codes shall be made by the Director of Facilities and Grounds or his/her designee. | |||
| I, hereby declare that I need access requested to assist me in the performance of my assigned job duties. I affirm that I will not attempt to have, or allow, any keys, access cards, or access codes issued to me to be duplicated, altered or distributed to others. If I am transferred or leave the employment of North Crockett Public Schools, I will return the key(s), access cards, and access codes issued to me to the Director of Facilities and Grounds or his/her designee. Further, should I lose a key(s), access card, or access code, issued to me I will report the loss immediately to the Director of Facilities and Grounds at the following number: | |||
| Signature (your name): _________________________________________ Date: ____________________________ | |||
| Departmental Approval: I have received this request and approve the issuance of the key(s), access card or access code requested. | |||
| Signature (principal): _______________________________ Date: ______________ Phone #: __________________ | |||
| Director of Facilities and Grounds: Date: | |||
Appendix B Glossary of Terms and Definitions
Some of the terms defined in this appendix may not be commonly used in a school environment. However, this appendix is meant as a resource for the reader should a locksmith need to be called in to address a lock issue in a school.
All-section key blank The key section that enters all keyways of a multiplex system.
Bitting 1. The number(s) that represent(s) the dimensions of the key; 2. The actual cut(s) or combination of a key.
Bitting list A listing of all the key combinations used within a system. The combinations are usually arranged in order of the blind code, direct code, and/or key symbol.
Bow The portion of the key that serves as a grip or handle.
Bumping One of many methods used to open locks with the use of “bump keys” that leave no sign of physical attack.
Cam 1. A lock or cylinder component that transfers the rotational motion of a key or cylinder plug to the bolt works of a lock. 2. The bolt of a cam lock.
Change key 1. A key that operates only one cylinder or one group of keyed-alike cylinders in a keying system. 2. Any device that is used to mechanically or electronically allow resetting of certain key or combination locks.
Combinate To set a combination in a lock, cylinder, or key.
Composite keyway A keyway that has been enlarged to accept more than one key section, often key sections of more than one manufacturer.
Construction core An interchangeable or removable core designed for use during the construction phase of a building. The cores are normally keyed alike and, upon completion of construction, they are to be replaced by the permanent system’s cores.
Construction master key (CMK) A key normally used by construction personnel for a temporary period during building construction. It may be rendered permanently inoperative without disassembling the cylinder.
Control key 1. A key whose only purpose is to remove and/or install an interchangeable or removable core. 2. A bypass key used to operate and/or reset some combination-type locks. 3. A key that allows disassembly of some removable cylinder locks.
Controlled cross keying A condition in which two or more different keys of the same level of keying and under the same higher level key(s) operate one cylinder by design: e.g., XAA1 operated by AA2. Note: This condition could severely limit the security of the cylinder and the maximum expansion of the system when (1) more than a few of these different keys operate a cylinder or (2) more than a few differently cross-keyed cylinders per system are required.
Core A complete unit, often with a figure eight shape, which usually consists of the plug, shell, tumblers, springs, plug retainer, and spring cover(s). It is primarily used in removable and interchangeable core cylinders and locks.
Cross keying The deliberate process of combinating a cylinder (usually in a master key system) to two or more different keys which would not normally be expected to operate it together. See also controlled cross keying and uncontrolled cross keying.
Cut key A key that has been bitted or combinated.
Day key 1. The key for a day gate or day operation of a safe or vault lock. 2. A cash register key that does not allow audit or reset functions. 3. See change key.
Disposable construction core Used with interchangeable core keying, where nonessential locking doors are used within a construction project. Locks are supplied with disposable plastic cores.
Dummy cylinder A nonfunctional facsimile of a rim or mortise cylinder used for appearance only, usually to conceal a cylinder hole.
High security cylinder A cylinder that offers a greater degree of resistance to any two or more of the following: picking, impressioning, key duplication, drilling, or other forms of forcible entry.
Housing The part of a locking device that is designated to hold a core.
Interchangeable core A key removable core that can be used in all or most of the core manufacturer’s product line. No tools (other than the control key) are required for removal of the core.
Key bitting array (KBA) A matrix (graphic) display of all possible bittings for change keys and master keys as related to the top master key.
Key cabinet A cabinet with hooks, Velcro, or other means designed to store keys systematically.
Key changes The total possible number of different keys available for a given type of tumbler mechanism.
Key control Any method or procedure that limits unauthorized acquisition of a key and/or controls distribution of authorized keys. A systematic organization of keys and key records.
Key interchange An undesirable condition, usually in a master key system, whereby a key unintentionally operates a cylinder or lock.
Key section The exact cross-sectional configuration of a key blade as viewed from the bow toward the tip.
Key symbol A designation used for a key combination in the standard key coding system, e.g., A, AA, AA1, etc.
Key system schematic A drawing with blocks utilizing keying symbols, usually illustrating the hierarchy of all keys within a master key system. It indicates the structure and total expansion of the system.
Keyed alike (KA) Of or pertaining to two or more locks or cylinders which have or are to have the same combination. They may or may not be part of a keying system.
Keyed different (KD) Of or pertaining to a group of locks or cylinders, each of which is or is to be combinated differently from the others. They may or may not be part of a keying system.
Keying Any specification for how a cylinder or group of cylinders are or are to be combinated in order to control access.
Keying schedule A detailed specification of the keying system listing how all cylinders are to be keyed and the quantities, markings, and shipping instructions of all keys and/or cylinders to be provided.
Keyway 1. The opening in a lock or cylinder that is shaped to accept the key bit or blade of a proper configuration. 2. The exact cross-sectional configuration of a keyway as viewed from the front. It is not necessarily the same as the key section.
Large format interchangeable core (LFIC) 1. A key removable core that can be used in all or most of the core manufacturer’s product line. No tools (other than the control key) are required for removal of the core. Recognized as a core having a universal figure 8 shape, and is generally unique in size to a specific manufacturer. An interchangeable core that is too large to fit into a small format interchangeable core housing.
Levels of keying The divisions of a master key system into hierarchies of access.
Master key 1. A key that operates all the master keyed locks or cylinders in a group, each lock or cylinder usually operated by its own change key. 2. To combinate a group of locks or cylinders such that each is operated by its own change key as well as by a master key for the entire group.
Master key system 1. Any keying arrangement that has two or more levels of keying. 2. A keying arrangement that has exactly two levels of keying.
Master keyed Of or pertaining to a cylinder or group of cylinders that are or are to be combinated so that all may be operated by their own change key(s) and by additional key(s) known as master key(s).
Multiplex key system 1. A series of different key sections that may be used to expand a master key system by repeating bittings on additional key sections. The keys of one key section will not enter the keyway of another key section. This type of system always includes another key section that will enter more than one, or all of the keyways. 2. A keying system that uses such keyways and key sections.
NMK A notation used to indicate "not master keyed" and is suffixed in parentheses to a regular keying symbol. It indicates that the cylinder is not to be operated by the master key(s) specified in the regular keying symbol, e.g., AB6 (NMK).
Pattern key 1. An original key kept on file to use in a key duplicating machine when additional keys are required. 2. Any key that is used in a key duplicating machine to create a duplicate key.
Pin tumbler Usually a cylindrical-shaped tumbler. Three types are normally used: bottom pin, master pin and top pin.
Plug The part of a cylinder that contains the keyway, with tumbler chambers usually corresponding to those in the cylinder shell.
Removable core A key removable core that can only be installed in one type of cylinder housing, e.g., rim cylinder or mortise cylinder or key-in-knob lock.
Selective master key An unassociated master key that can be made to operate any specific lock(s) in the entire system in addition to the regular master key(s) and/or change key(s) for the cylinder without creating key interchange. Examples include: (ENG) engineering key, (HSKP) housekeeping key, (JAN) janitor’s key, (SEC) security key, (GRND) grounds key.
Shear line A location in a cylinder at which specific tumbler surfaces must be aligned, removing obstruction(s) that prevent the plug from moving.
Shell The part of the cylinder that surrounds the plug and usually contains tumbler chambers corresponding to those in the plug.
Simple key section A single independent key section which cannot be used in a multiplex key system.
Single key section An individual key section which can be used in a multiplex key system.
SKD Symbol for “single keyed,” normally followed by a numerical designation in the standard key coding system, e.g., SKD1, SKD2, etc. It indicates that a cylinder or lock is not master keyed but is part of the keying system.
Small format interchangeable core (SFIC) 1. A key removable core that can be used in all or most of the core manufacturer’s product line. No tools (other than the control key) are required for removal of the core. 2. Recognized as a core having a universal figure 8 shape, and is small in size.
Standard key coding system An industry standard and uniform method of designating all keys and/or cylinders in a master key system. The designation automatically indicates the exact function and keying level of each key and/or cylinder in the system, usually without further explanation.
Surreptitious entry The use of entry or bypass techniques that cannot be detected via disassembly and detailed inspection of lock components.
Tailpiece An actuator attached to the rear of the cylinder, parallel to the plug, typically used on rim, key-in-knob or special application cylinders.
Top master key (TMK) The highest level master key in a master key system.
Uncontrolled cross keying A condition in which two or more different change keys under different higher level keys operate one cylinder: e.g., XAA1, OB (operated by) AB, AB1.
Note:This condition severely limits the security of the cylinder and the maximum expansion of the system, and often leads to key interchange.
Visual key control (VKC) A specification that all keys and the visible portion of the front of all lock cylinders be stamped with standard keying symbols. Symbol used in hardware schedules to indicate a cross-keyed condition for a particular cylinder: e.g., XAA2, OB (operated by) AA3, AA4, AA, A.
Zero bitted Of or pertaining to a cylinder which is or is to be combinated to keys cut to the manufacturer's reference number “0” bitting.