Steel frame

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A steel frame is a door frame made from sheet steel .


In the mid-1920s, the Frankfurt master locksmith August Schanz developed such a door frame made of folded sheet steel. He was part-time city councilor in Frankfurt am Main and befriended the city architect Ernst May . At that time May was in charge of the Neues Frankfurt project , which was working on the urban renewal of Frankfurt. Great importance was attached to typification and standardization, and it was hoped that innovative products would lead to increased quality and cost savings. So Ernst May and August Schanz came up with the idea in the course of simplifying the construction. The men called this frame “ frame ” based on the term used in carpentry. The steel frame was used for the first time in all buildings in the new Frankfurt.

As early as the mid-1930s, such a steel door frame was manufactured with a sealing cord to reduce the closing noise. At that time, some manufacturers in Germany also made frames from rolled profiles. In the long run, however, it was unsuccessful and too expensive, and technically too little variable.

After the war, steel frames began to triumph when reconstruction began in Germany. The Stahl-Schanz company took great care of the further distribution, because their development manager Karl Stumpp first created a company standard for steel frames, these were the manufacturer's preferred dimensions. He then implemented the first generally applicable DIN standard in the early 1960s . Karl Stumpp also had the idea of ​​delivering the standardized steel frame plus standardized wooden door as "one component" - and that directly to the construction site at different times, but precisely.


Logo of the German Institute for Standardization DIN 18111-1 to -4
Area Construction
title Door frames - steel frames
Latest edition 2004 (part 1, 2 and 4), 2005 (part 3)

A frame is a frame consisting of four parts: head bar, ribbon bar, lock bar, held together as a steel frame and supported by a transport rail, also known as a mounting bracket. When put together, a frame forms the connection between the wall and the door, the door leaf is "hinged" to the frame, that is, fitted and, when closed, lies in the frame. Frames are delivered assembled or disassembled and assembled on the spot because it is very expensive to transport bulky parts.

Different types of frames are known; they are described in the DIN standard DIN 18111 . This standard was first published at the end of the 1950s, revised in 1974 and has been in the form that is still valid since January 1985. This standard was revised again at the beginning of the 21st century and has been available in three parts since August 2004:

  • DIN 18111-1 - Standard frames for rebated doors in masonry walls
  • DIN 18111-2 - standard frames for rebated doors in stud walls
  • DIN 18111-3 - Special frames for rebated and unrebated door leaves
  • DIN 18111-4 - installation of steel frames

“This guideline does not apply to steel frames for fire and smoke protection barriers, for burglar-resistant or sound-absorbing elements, air protection doors, frames for container construction, for sandwich walls and timber frame construction as well as for steel frames in concrete walls in the pouring process. The relevant standards and regulations must be observed. "


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Z frame, corner frame, Z frame or corner frame with supplementary frame, also called counter frame and surrounding frame. These designations have established themselves for all frames, whatever material they are made of. Here and there you still come across old expressions such as block frame or frame. The carpenter knows this expression and uses it to describe a grooved rod that is inserted directly into the wall at a corner, the door leaf is then attached to it. A kind of corner frame, if you will. However, frames are also manufactured in all sorts of other shapes, with a shadow groove, for double doors, for swing doors , for sliding doors , etc. The manufacturers' catalogs provide information.

The industry understands special frames to mean frames for unrebated doors, i.e. those that fold in butt and flush, lie flat in the frame, rebated doors protrude slightly, as well as frames that are not produced in standard dimensions. Floor-to-ceiling frames, with and without a skylight, are also produced. (see Fig. 1) Fig. 2 shows the variations in which steel frames are manufactured today.

The retrofit frame has been around for a few years. It is blinded over an existing steel frame, pushed and fastened in a special way according to the manufacturer's instructions. There are such frames in particular for burglar-resistant doors and for fire doors according to the provisions on "Changes to fire doors", published in the notification of the German Institute for Building Technology, Berlin, 1/96.

For some years now, steel frames have been manufactured that can be installed either DIN left or DIN right. This reduces storage and allows later changes in the direction of rotation. This is very easy to do if a door that sits in a color-treated frame needs a different direction of rotation. In most frames today, belt pockets are provided on both sides with the corresponding holes for fastening as well as locking slots and wall protection boxes. The desired locking slots only have to be opened, they are pre-cut.

The term “frame” is not only defined for the connection from door to wall, but window frames have also been known for many years. Again, these are frames that are set in the wall and later accommodate windows.

Figure 3 shows a window frame that is prepared for internal blinds.

Frames for fire doors are made very differently. They are available edged, made of drawn steel profiles, wooden or aluminum profiles and combinations. Usually strips and cords are inserted with a special, foaming and therefore fire-retardant effect. Steel frames for fire doors contain such a strip; it is hidden behind a thin-walled angle and lies in the rebate of the frame. At 100 ° C, the material swells and presses open the thin leg of the bracket so that the gap between the frame and the door leaf is closed and sealed.


The recesses for the lock latch and lock bolt are to be pre-punched on the two side parts of the frame so that they can be exposed on the construction site with light hammer blows for the doors to be hinged on the right or left. This has proven to be useful, so the specification DIN right or DIN left is omitted. Frames that are equipped in this way with the recesses for the lock latch and bolt can be used for both DIN right and DIN left-hinged doors. A meter mark is always punched inside the lower locking slot. The lower edge of the upper locking slot corresponds to the handle height of 1050 mm measured from the upper edge of the finished floor. Locking slots are provided on both sides of steel frames, but locked, in the lock rod as in the ribbon rod, so that they can be used on the left and right.

One long side is punched out in a semicircle at both locking slots. At this point, rework can be done so that the door closes better.

The wall protection box behind the strike plate and the locking slots must be "professionally spotted" by the manufacturer of the steel frames, i.e. correctly, durable and fastened. It was developed so that the space remains free when backing mortar, back pouring, foaming and latch and bolt can intervene.

In order to dampen the closing noise, but at the same time to protect against drafts, a groove was worked into the steel frame, which accommodated a rubber cord.

In the past, 2 lower parts of the hinge were first welded, plugged and then screwed onto the steel frames. Later the ribbons used became smaller and more delicate. Belts consist of 2 parts: a bottom part and a top part. The lower part is attached to the frame; the top band on the door. Both parts come together when the door is hung and so the two-part hinge supports the door. And belt bags were developed many years ago. These are small pockets made of sheet steel, which are attached to the back, slots are let in at the front, through which any band lower parts can be inserted and fastened.

The side parts of the frames are always 3 cm longer than necessary; they mark the "floor inset". These 3 cm must be embedded in the floor for the stability of the frame. Exceptions can be found in the "Changes to fire protection barriers".

Today steel frames are mostly dip-primed, that is, made from hot-dip galvanized sheet steel using a roll-forming process and welded together or prepared for plugging together. Then the parts are cleaned, degreased, phosphated, rinsed, immersed in the electrical process and baked. This coat of paint is not a finishing coat, even if it looks and is often viewed that way. DIN 18111 for steel frames requires a primer coat, on which a top coat and top coat are then applied.

Before installation, the steel frame must be checked for squareness and any misalignment that may have occurred during transport must be professionally corrected. The steel frame must be aligned according to the meter plan near the door and fixed vertically and flush in the wall opening using assembly aids. For this purpose, the slightly inwardly curved steel frame, which is slightly pre-tensioned in an X-shape, is to be spread out so that the deflections to be expected from the backfilling are absorbed and the frame rebate is maintained from the entire height.

The frame must then be backfilled with mortar according to DIN 1053-1.

Steel frames have the advantage that they are very firmly attached to the wall.

Individual evidence

  1. History of the steel frame on ( Memento of the original from May 6, 2014 in the Internet Archive ) Info: The archive link was automatically inserted and not yet checked. Please check the original and archive link according to the instructions and then remove this notice. (PDF file; 805 kB) @1@ 2Template: Webachiv / IABot /