Skip to main content

Security doors S4

The high-performance system within the SÄLZER security door range.

Combined protection for the most exacting security requirements

The S4 steel series is the high-performance system in the SÄLZER range of security doors. It offers maximum certified protection against break-ins up to RC6, bullets up to FB7-NS and explosions up to a reflective pressure of 2,750 kPA (EXR5, 20 kg | 4 m).Furthermore, the protective function of the high-security doors has been checked as part of the blast test (e.g. 500 kg of explosives | distance of 28 m).

It also provides protection against the effects of accidents, for example in the petrochemical industry, with long-lasting shock waves. In addition, fire and smoke protection up to T90/EI90/S200 can be provided depending on the design, place of use and the other security requirements.

Security requirements
Forced Entry Resistance to RC6
Bullet Resistance to FB7-NS
Blast Resistance
Smoke to S200
Fire to EI90
More about the safety levels

The steel door won the German Design Award 2018. The steel door offers individual design options despite the high security properties. The German Design Award directly contributes to the overall commercial success. Prizes will only be awarded to projects that truly represent pioneering contributions to the German and international design landscape.

The following test video shows the forced entry test of the steel door, level RC 5/RC 6 at an accredited test institute.

Security according international standards & individual requirements

Steel door S4 series

Forced entry resistance
Forced entry resistance
According to DIN EN 1627-1630 up to RC6.
Bullet resistance
Bullet resistance
According to DIN EN 1522-1523 resp. glazing according to DIN EN 1063 up to FB7-NS resp. glazing up to BR7-NS.
Blast resistance
Blast resistance
In accordance with Din EN 13123-2 and DIN EN 13124-2 up to EXR5, reflected pressure of 2,750 kPa (20kg | 4 m). Tested in accordance with customised requirements with different explosive charges e.g. 100 kg in 10 m or 500 kg blasted in 28 m. Sector specific tests e.g. for the petrochemical industry, double door glazed door, peak pressure pmax = 93 kPa, positive pressure duration t+total = 4.5 sec. Glazing according to SÄLZER specification. Classified: GSA 2 (Protection Level, „Very High“), ISO B (Hazard-Rating, „No Hazard“).
Fire resistance
Fire resistance
Depending on the design variant and further protection, fire protection up to T90/EI90, EI45,T30/EI30. Tested in accordance with British Standard BS 476: 120 Min. (actual test duration 150 Min.).
Smoke resistance
Smoke resistance
Depending on the design variant and further protection, smoke resistance upt to S200.

Higher security requirements can also be met at the customer's request. We would be happy to help put together your security concept in a personal consultation.

Types | installation depth |glazing | surface


Door leaf thickness

Depending on the security level, the door leaf thickness is between 72 mm and 165 mm. The door leaf consists of an internal extremely torsion-resistant and patented construction of thick-walled profiles, which allow the integration of all security reinforcements and inserts and stiffen the door leaf under extreme stress. In addition the door leaf is secured with
1.5 mm thick galvanized steel-claddings on both sides. All security components inside the door leaf are firmly connected with the whole construction. In the lock area, additional reinforcement plates are welded on to stabilize the lock.


Large doors are tested e.g. single door forced entry resistant in level RC4, leaf measurement 2,000 x
4,000 mm. Recommended door size up to 1.250 x 2.500 mm, size depends on the door leaf weight and on the place of installation (bi-metal effect).


Galvanized and coated, over clad with timber, stainless steel, stone, bronze and other options.

Resistance against wind load

Depending on the type up to level C5 (test pressure: 2.000 Pa)

Water tightness

Depending on the type up to level E 2,700 (test pressure: 2,700 Pa)

Air permeability

Depending on the type up to level 4 (test pressure: 600 Pa)

Impact resistance

Depending on the type up to level 5 (drop height: 950 mm)

Thermal insulation

Depending on the type up to UW 2,2 W/m²K

Sound insulation

Depending on the type up to RW 50 dB

Life cycle test

Suitable for frequently used entrances and exit, 200,000 open and closing cycles

Furner technical properties

Locks | fittingsAll locks which are approved in the tested security class of the door. Mechanical, electro-mechanical or motorized locks, single or multiple locking. Doors for emergency exits tested according to DIN 179 and DIN 1125 (panic bar) up to RC4. Applicable as interlocking door with special control system possible. All tested and certified fittings can be in-stalled in the respective security level. In resistant level RC5/RC6 equipped with an additional bolt work.

Hardware | weight

Hinges are designed for high weights. Ease operation despite high leaf weights. Leaf weights up to
600 kg, turn wing gates up to 1,000 kg and sliding gates up to 5,000 kg leaf weight
Threshold | door rebateT3-sided door rebate, alternative 4-sided door rebate. Threshold design: adjustable floor seal, bullet resistant floor connection or threshold, custom-made threshold in steel or stainless steel with/without seal, option: accessible entrance for people with impairments/disabilities (barrier-free).
FramesCorner frame (standard), block frame (for the flush installation into the opening), edge and counter frame (depending on the walll thickness available in 3 different versions).
InstallationInstallation in several building materials is permitted.
Bullet resistance: a bullet resistant wall connection is tested and recommended.


Areas of application

Area of application: industrial company.

Double steel door, indoor use, with fire protection.

Personal consultation

Every building project is unique and the perfect high-security solution depends on a number of different factors. Contact us now and we will work out your requirements together, so that you can have the perfect security system and protect what is yours and what is important.



Contact us now