Series S4 – just safe is not enough

The high-performance system within the SAELZER security door range. For highest safety classes in forced entry resistance (up to RC6), bullet resistance (up to FB7-NS), blast resistance (pressures up to 27,3 bar/500kg of explosives) plus optional fire and smoke protection up to ratingsT90/EI90/S200. Nearly unlimited design variants. Multi-functionality without compromising design, elegance and comfort features.


Safety classes:

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.


  • Blast resistant steel door:

    Blast resistant steel door:

    tested with long pressure duration of 1.000 ms, level GSA2. Application: pumped storage hydro power plant.

  • Security steel door series S4 clad with timber.

    Security steel door series S4 clad with timber.

  • Double door with glazing.

    Double door with glazing.

  • Forced entry resistant steel double door:

    Forced entry resistant steel double door:

    clad with a mullion-transom facade. Size: 3,940 x 5,260mm.


The following test video shows the forced entry test of the steel door, level RC5/RC6 at an accredited test institute.


» Technical data

Security doors steel series S4
Types | installation depth | glazing
ST01 T 1flgST02 T 1flg LA kleinST03 T 1flg LA großST04 T 1flg ST STST05 T 1flg LA klein ST OLST06 T 2flgST07 T 2flg LA kleinST08 T 2flg LA großST09 T 2flg ST STST10 T 2flg LA groß ST ST OL
Door leaf thickness
72 mm - 141 mm depending on the security level
hoehe und breite
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).
Anodised or powder coated, over clad with timber, stainless steel, stone, bronze and other options.
Security according international standards & individual requirements
Forced entry resistance*
According to DIN EN 1627-1630 up to RC6
Bullet resistance*

AAccording to DIN EN 1522-1523 resp. glazing according to DIN EN 1063 up to FB7-NS resp. glazing up to BR7-NS.

Blast resistance*
According to DIN EN 13123 up to EXR5, reflected pressure of 272 kPa (2.72 bar)
Tested according to customised requirements with different explosive charges (such as 100 kg, 200 kg or 500 kg charge) blasted in various distances e.g. 10m, reflected pressure up to 880 kPa (8.8 bar)
Individual tests with a long duration pressure up to 4,500ms, reflected pressure 93 kPa (0,93bar)
Classification: GSA2
Performance according to DIN EN 14351
Forced entry resistance
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
200.000 open and closing cycles
Furner technical properties
Locks | fittings All 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 rebate T3-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).
Corner 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).
Installation Installation in several building materials is permitted.
Bullet resistance: a bullet resistant wall connection is tested and recommended.

*other or higher requirements upon request

» Download brochure: Steel doors series S4 pdf