The Where, Why and How of Ligature Resistant Locks

Aug. 30, 2013
Door hardware manufacturers offer these specialized security solutions for use in behavioral units, psychiatric facilities and other places of incarceration. The goal of ligature resistant hardware is to limit possibilities of personal harm.

As needs arise, the door hardware industry develops products to meet those needs. Door closers were reportedly invented after someone complained about the noise from slamming doors during a worship service. Exit devices were said to have been developed after locked doors caused hundreds of people to perish during a fire at a Chicago theatre.

In more modern times, the need to protect patients and prisoners in psychiatric facilities and other places of incarceration has risen to the forefront.  And once again, the door hardware industry has stepped forward to provide an alternative to traditional products that keeps the safety of these incarcerated individuals in mind. 

In addition to security and reliability, traditional door hardware products are designed for ease of use and visual appeal; however, these aspects are of much less importance for incarceration facilities. The possibility of persons injuring or killing themselves by tying a cordlike object to projecting hardware components has spurred door hardware manufacturers to develop new shapes and designs to limit this risk. 

This new type of hardware has been referred to by several different names. The original term was anti-ligature, with ligature defined as tying or binding. This term evolved into today’s ligature resistant door hardware. These locks may also be referred to as behavioral health hardware or institutional safety hardware.

Many incarcerated individuals — whether in prison, a mental health facility or similar establishment — are potentially at risk for suicide attempts. Because of their function, door and lock hardware is solidly mounted; thus, a door handle offers a reasonable opportunity for an individual to use it as an anchor point for a noose or other cordlike objects while they are confined in a small room.

This situation is where ligature resistant hardware is applicable. It is designed to limit the possibilities of personal harm by restricting the attachment of a cordlike object to door closers, hinges, knobs, levers and handles that are designed to not release under abnormal load.

For security, ligature resistant hardware is installed with the locking mechanism controlling the inside of the door while still providing unrestricted access from the exterior side of the door. Most exposed surfaces on ligature resistant door and lock hardware have sloped or curved corners to resist attachment of a cordlike object. 

Installation Alternatives

When considering ligature resistant door hardware solutions, there are two options: installing new hardware or retrofitting the surface-mounted components while still using the existing mortise lock chassis.

While most doorknobs are cone-shaped, manufacturers offer semi-circular lever handles which are retained in a baseplate for ligature resistance.  An installation alternative to knobs and levers can be a push-pull paddle trim installed in a downward position to resist cord attachment. Another installation alternative is concealed products. For example, door closers can be mounted in the header or into the floor with the arm only exposed when the door is open.

A number of lock manufacturers offer ligature resistant solutions for correctional and healthcare facilities, including Best Access Systems, Corbin Russwin, Sargent, Schlage and Town Steel. In addition to lock manufacturers, hinge manufacturers such as Ives, McKinney and Select Hinges offer ligature resistant butt or continuous hinges.

Important: Before purchasing or installing any ligature resistant hardware, discuss the application with the local agency having authority (LAHJ). If you are providing services for a hospital or healthcare facility, contact the state agency which inspects these facilities. Each state may have specific local rules and regulations.


Some lock manufacturers do not recommend retrofitting ligature resistant parts into existing mortise locks. Consult the lock manufacturer before purchasing or beginning an installation which requires retrofitting.

When retrofitting a mortise lock to ligature resistant knobs or levers, the mortise lock must be equipped with the same style of hardware. For example, a mortise lock designed for levers has a stronger return spring force to insure that the levers will return to a horizontal position after each use. Installing knobs on this type of mortise lock can result in knobs being difficult to turn in order to retract the latch. If ligature resistant levers are installed in a mortise lock which was designed for knobs, the levers may eventually droop and possibly hold the latch in a retracted position.  

When retrofitting ligature resistant levers to existing mortise locks, consider lever rotation. To be effective, a mortise lock must allow enough rotation to at least disengage any cordlike object when the lever is rotated. A lever-equipped ligature resistant lock must also have some kind of clutching mechanism on the locking side of the door. If a cordlike object is attached to the locked lever, the disengaging clutch mechanism will allow the lever to rotate and disengage the cordlike object.

When customers request ligature resistant products, work closely with your local locksmith distributor or/and consult product manufacturer representatives to verify that the ligature resistant hardware you will be installing is the best available solution for your specific customer requirements. 

Manufacturers’ Offerings

Most manufacturers offer specific ANSI/BHMA Grade 1 products for specific applications. For example, Sargent Lock offers a series of Behavioral Health Trim for their 8200Mortise Locks. Included in this series are the BHW trim that integrates lever and the escutcheon; the BHL lever trim that offers an overlapping rose; and the rounded ALP paddle trim (also available in bored lock). Each of these products was designed for different risk levels in a behavioral health facility with the BHW appropriate for use in high risk areas.

Marks USA offers LifeSaver cylindrical locksets with ligature resistant knobs, levers and paddlesets, and mortise locks with knob or paddleset. Marks’ knob equipped mortise locks can be retrofit with ligature resistant hardware.

Corbin Russwin offers Behavioral Health Trim for its ML2000 and ML20900 Mortise Lock options. This series offers an integrated lever and escutcheon, the BHSS; a sloped surface lever and rose, the BLSS; and paddle trim. The integrated lever and escutcheon trim (BHSS) is accepted for use in high risk areas. The four-position paddle trim is also available with the HP3000 Series Tubular Lock.

Schlage offers mortise locks with ligature resistant knobs, levers, thumbturns and cylinder rings. The ligature resistant levers have an integrated clutch that allows the lever to rotate in event of excessive force. Best Access Systems offers mortise locks and non-keyed tubular locksets with ligature resistant hardware. Town Steel produces ligature resistant Grade 1 mortise locks, Grade 1 and 2 cylindrical locks and Grade 1 mortise deadlocks. In addition to the knob and lever versions, mortise locks are available with the Trim-Arch; a handle operates by pushing down.

Town Steel’s ligature resistant Rejuvenator system can upgrade specific mortise lock brands to accept a ligature resistant knob. A patented mounting plate retrofits onto various lock manufacturers' knob-style mortise lock cases. Contact Town Steel for specifics.

For inward swinging doors, ligature resistant hinges deter a cordlike object from remaining attached to the exposed portion of the hinge. Select Products Limited offers a ligature resistant steeple for their geared, full surface continuous hinge. The wedge-shaped steeple is attached to the header above the continuous hinge. Ives, McKinney and other butt hinge manufacturers offer hinges with the knuckle trimmed at an angle to resist ligature.

While ligature resistant door hardware vastly decreases the risk of an incarcerated individual using door hardware as an anchor point, they are certainly not fool-proof. A paragraph in Sargent Lock spec sheets for its behavioral health products sums it up by noting that ”although these products are better designed for behavioral health applications than traditional trim, they do not eliminate the risk that an object can be affixed to, or around them." 

For more information on the companies discussed in this article, contact your local distributor or:

Best Access System:

Corbin Russwin:


Marks USA:

SARGENT Manufacturing:


Select Products:

Town Steel:

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