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Hollow metal frames are widely used in hospitals, schools, offices, warehouses, and other commercial buildings because of their strength, durability, and versatility. They are typically manufactured by forming sheets of steel into specific profiles, with the frame design determining how the door fits within the opening and how it works with the surrounding wall and hardware.
If you're sourcing hollow metal frames for a project, This guide will walk you through everything you need to know to make the perfect choice for your facility.
A hollow metal door frame is a frame made from formed sheet metal, typically steel, that supports a door within a wall opening. It provides the mounting points for the hinges and strike, helps maintain the door's alignment, and transfers loads to the surrounding wall structure through its anchoring system.
A typical frame consists of three main sections: two vertical jambs and a horizontal head. Depending on the application, it may also include hinge reinforcements, strike preparations, anchors, silencers, and other hardware-related details.
In the construction industry, terms such as “hollow metal frames,” “steel door frames,” “commercial metal frames,” and “commercial steel frames” are often used interchangeably. However, these terms alone do not define the exact specifications required for a project.
Hollow metal frames are available in different configurations to suit wall construction, installation methods, and door arrangements. The following types serve different purposes, so it is useful to understand what each one is designed to do.
Masonry frames are typically installed in concrete block, brick, and other masonry walls. Their sturdy construction makes them a common choice for commercial buildings, warehouses, and industrial facilities.
Before ordering, check the wall dimensions, anchoring requirements, and installation sequence. For fire-rated openings, the frame must also meet the specifications of the required door assembly.
In offices, schools, healthcare facilities, and other commercial interiors, hollow metal frames are often installed in drywall partitions built with metal or wood studs. Knock-down (KD) frames are a popular option because they can be assembled around an existing wall opening, making installation more convenient in many situations.
Wall thickness is an important detail to get right. Check the finished wall dimensions and confirm that the frame and its anchors are suitable for the partition before placing your order.
A double egress frame accommodates two door leaves that swing in opposite directions. You'll often find this configuration in commercial corridors and other areas where the building layout calls for doors to open in opposing directions.
The frame needs to match the door arrangement and hardware specifications. If the opening is part of a fire-rated assembly or a required means of egress, check the applicable requirements before finalizing your order.
An adjustable frame offers more flexibility when wall thicknesses vary or aren't fully confirmed at the time of ordering. It can accommodate a specified range of wall depths, helping simplify installation when actual site conditions differ within that range.
Keep in mind that every adjustable frame has its limits. Check the manufacturer's adjustment range, installation instructions, and hardware compatibility to make sure the frame will fit your opening.
Choosing a hollow metal frame starts with the opening and the wall, not simply the door size. A few checks at the beginning of a project can make the ordering process more accurate and reduce the need for changes after delivery.
Identify the wall construction, finished wall thickness, and installation stage. These details help determine the correct frame dimensions, jamb depth, and anchoring method.
Choose the appropriate steel thickness based on traffic levels, expected wear, security needs, and project specifications. Thicker steel may be required for demanding applications.
Verify the opening size, jamb depth, frame profile, and anchor type. Matching these details to the wall construction helps ensure proper fit, alignment, and secure installation.
Check the required fire rating and applicable project codes. The frame, door, hardware, and installation must be compatible with the specified fire-rated assembly.
Specify hinge locations, strike preparations, closer reinforcement, and other required hardware cutouts. Confirming these details before fabrication helps reduce field modifications and installation delays.
Many frame-ordering problems do not come from complicated technical issues. They come from details that were assumed, left out, or confirmed too late.
Here are several worth checking before an order is released for production.
Providing only a nominal door size leaves important questions unanswered. The supplier may still need the rough opening, frame dimensions, wall thickness, and other information to determine the correct configuration.
The solution is straightforward: provide the relevant drawings or confirm each dimension explicitly. If the opening is based on an existing condition, state what was measured.
The wall thickness shown on early drawings may not reflect the final construction. Additional board layers, finishes, or changes to the partition specification can affect the required frame throat.
Confirm the intended finished wall thickness and check that it falls within the frame's specified dimensions or adjustment range. This is especially important when multiple wall types appear on the same project.
A frame can be dimensionally correct and still be unsuitable if the hinge or strike preparations do not match the specified hardware.
Before production, coordinate the hardware schedule with the frame requirements. If changes are still possible, make that clear so the relevant details can be resolved before the order is finalized.
Material alone does not establish a frame's fire rating or suitability for a specific regulated application. Where ratings or other performance criteria apply, the frame must meet the relevant requirements as part of the specified assembly.
Review the project documents before ordering and confirm any necessary labels, approvals, or compatibility requirements with the supplier.
A useful final check is to compare the frame order against the door schedule, hardware schedule, wall details, and project specifications. Resolving discrepancies before production is generally easier than correcting them after the frames arrive on site.
The main difference is the wall construction and the way the frame is installed and anchored. Masonry frames are designed for masonry openings, while drywall frames are intended for partition systems using gypsum board over studs or other compatible construction.
The correct choice depends on the actual wall assembly and installation sequence. The names alone are not enough to determine compatibility.
No. Knock-down describes a frame supplied in separate components for assembly, while drywall describes a wall construction or application. Knock-down frames are commonly used with drywall partitions, but frame type and installation compatibility should always be confirmed against the manufacturer's specifications.
Yes, when the selected frame is appropriate for the required fire-rated assembly and meets the applicable listing, labeling, and installation requirements.
The frame should not be considered fire-rated simply because it is made of steel. Confirm the specified rating and compatibility requirements for the complete opening assembly before ordering.
The main difference between welded and knock-down (KD) door frames is how they are assembled. Welded frames are factory-welded into a rigid unit and are commonly used in new construction, while KD frames are shipped in separate pieces and assembled on-site, making them easier to transport and often more suitable for finished drywall openings. The right choice depends on the wall construction, installation sequence, and project requirements.
