MS4043 Cylinder Guard

MS4043 Cylinder Guard is a hardened-steel ring to protect cylinder from vandalism.


The standard mortise cylinder is made of brass. It is literally a soft spot in narrow stile door security. Using special pliers, a pipe wrench or other leverage device, a burglar can tear the cylinder out of the door, leaving an opening through which the deadlock may be operated.

The MS4043 Cylinder Guard offers a three-way defense against this problem:

  1. The outer shield ring is fully beveled to offer poor purchase for either prying or twisting.
  2. The ring is hardened steel so that the combination of shape and hardness make it virtually impossible to grip, even with sharpened tools.
  3. In the event that a prying tool such as a cold chisel is driven into the stile behind the shield ring, the would-be burglar is obliged to pull a heavy steel plate through a round hole in the 1/8" metal door stile. This degree of leverage is far beyond that available with most hand tools.



Security Ring: Made of hardened-steel. Free swiveling when properly installed.

Retainer Ring: Hardened-steel, plated for corrosion resistance. Permits security ring to swivel.

Trim Finish: Powder coat 119 to match 335 Black anodized, 121 to match 313 Dark bronze anodized, 130 to match 628 Clear anodized

Standard Package: Individually packaged with spacers for flush fitting in thin stile walls. Cylinders available separately.

Shipping Weight: 1/8 lb. [0.06 kg]



MS4043 Cylinder Guard fits a standard 1/8" stile wall. For 1/4" thick stile walls, specify MS4043-01.

Compatible Products: This product is compatible with the following products:

Deadlocks Deadlatches Flushlocks Exit Devices
1830 SeriesMS1837 SeriesMS1850S Series, MS1850SN SeriesMS1861 Series1875 SeriesMS+1890 SeriesMS1950 Series, 2190 & 2290 Series

4300 Electrified Deadlatches

4510 Series4530 Series4900 Series4920AN Series

1870 Series1870HM Series Cylinder-Operated Flushbolts 8300 Mortise, 8400 Mortise