The steel grids KST4 are designed to secure rooms where a high level of security is required. They are used as additional protection of windows and doors or as the only safety barrier, e.g. dividing the corridor or room into zones and as protection of ventilation ducts, air intake, etc. The KST4 grids are made of steel bars ø20 with a maximum bar spacing of 120 mm and steel flat bars 6x45 with a maximum spacing of 400 mm, in a frame made of L-profile, C-profile or closed profile. The openable grid type KST4 and KST4K is suspended on two or three steel, welded hinges with ball bearings. The frame is made of steel sheet 3 mm thick. The grid can also be made on a shared frame with a door leaf. The KST4 grid can be equipped with multipoint lock or single-point lock, and the KST4K grid with certified fixation for padlock. The openable grids can be equipped with an electric strike, position contact, door closer and other equipment.
The grids can be additionally secured with a steel mesh made of 2 mm wire with fine mesh 10 x 10 mm or 20 x 20 mm in order to prevent documents or objects from being passed through the closed grid by unauthorized persons. The KST4 grids are made for windows and doors in single and double-leaf versions, and as partitions and structures in different dimensions. The grids are powder coated in RAL colors, and they are additionally zinc plated in the exterior.
The construction of the grid was tested in the IMP laboratory and obtained the RC4 burglary resistance class according to EN 1627: 2012. All critical components, such as vertical bars, hinges, and fixations for padlocks have been protected against cutting.