Ultra-tec stainless steel cable railing products are an excellent choice for a variety of commercial designs, offering unobstructed views and a spacious appearance. The most common use of cable railings in designs today are horizontally run cable railing system for interior and exterior applications.

The use of cable railings for commercial projects offer architects and designers flexibility, versatility, and a modern approach to any design. Cable railings also allow a creative and easy to install alternative for fabricators and installers. In addition to design and creativity, there are key design considerations for a successful cable railing system installation.

Stainless-Steel Cable Railing Strength

Cable, also referred to as wire rope or aircraft cable, is very strong in tensile strength and is designed to be flexible. The degree of flexibility varies depending on the cable’s diameter and construction (1×19, 7×7, 7×19, etc.), the tradeoff for flexibility is strength, and the opposite is also true.

For commercial projects or anywhere there is heavy pedestrian traffic, we recommend a 3/16-inch diameter cable (316-grade stainless steel). It is most commonly used and is durable, low-maintenance, and is attractive. For a variable aesthetic option, other diameters are available from 1/8-, 1/4-, 5/16-, and 3/8-inches.

Stainless-Steel Cable Railing Flexibility

Cable flexibility is an important consideration when designing a cable railing application. The International Residential Code (IRC) and International Building Code (IBC) require that a 4-inch sphere shall not pass through any portion of the installed railing. Because of this code requirement, the use of the most rigid of cable construction possible is ideal. Having the rigidity to prevent deflection of a horizontal run cable subjected to a vertical load is partly mitigated by the cable’s lack of flexibility.

The IBC requires cable designs to withstand a single concentrated load of 200 pounds applied in any direction at any point along the top. Also, attachment devices and supporting structures — handrails and guards — transfer the load to structural elements of the building.

Other factors include the tension — to at least 225 pounds — of the cable, the span between supporting intermediate members, the cable’s diameter, the vertical spacing of the cables on center, and temperature at the time of installation. Temperature fluctuations can cause variations in cable tension due to differing thermal expansion of the railing frame and the cable.  Depending on geographic locations, cable railings installed outdoors may experience large swings in temperatures; hot summer days to the cold winter nights may be a 140-degree difference.

The use of a stainless-steel railing frame virtually eliminates temperature-induced tension changes because it contracts and expands at the same rate as the stainless-steel cable.

Alternative materials like carbon steel, aluminum, and wood each expand differently than stainless and railing frames made from these materials and will exhibit varying cable tension with changes in temperature.

Post Spacing for Cable Railing

Intermediate posts or braces support the cable as it passes through the railing frame’s posts. An intermediate post is a structural post that runs from the top rail to the mounting surface, and a brace is a lighter weight material, supporting the cable and placed between posts.

While cable can run quite long distances (as much as 60-feet or more) between end posts, it will need support at intervals — intermediate posts or braces — to avoid cable deflection in excess permitted by building codes.

It is recommended to space posts or braces at a maximum of 48-inches with center cables 3-1/8-inches apart.

stainless-steel metal railing

Stainless-Steel Cable Railing Tension and Top Rail

Mounting and tensioning hardware is attached to end posts and work together to minimize the deflection. Posts must not deflect perceptively as the cables are tensioned to a minimum of 225 pounds at heights of 36- to 42-inches. It is crucial to minimize end post deflection, and potential bending, as an incredible amount of force is placed on the end post with ten or more lines.

A sturdy top rail is required to support the tensioning end posts and prevent bending under the strain of the tensioned cables. The most commonly used top rail for commercial use is stainless steel due to its resistance to corrosion and low maintenance.

Designing with Stainless Steel Vertical Railings

Vertical cable railings — cables run from the top rail to the bottom rail — are becoming increasingly popular to differentiate a project for either interior or exterior use. The building code requirements apply to vertical cable railings; however, the installation of vertical railings differ.

Framing material — pipe, or structural square or rectangular tube framing (stainless steel for exterior use) — with a minimum wall thickness of ¼-inch is ideal.  Cable braces are appropriate for replacing every eight cables to keep the top and bottom rails from bending when the cables are tensioned.

In this example, we recommend using the Invisiware® Threaded Stud on one end of the cable and screwed into a drilled and tapped hole in the underside of the top rail. An Invisiware® Receiver inserted into a hole drilled through the bottom rail. A threaded stud on the other end of the cable, tensioned by turning the receiver with an Allen wrench, completes the run.

Stainless steel cable railings and fittings offer a beautiful, low maintenance option to enhance interior and exterior designs. Ultra-tec products also contribute to LEED® credits benefiting architects, designers, and building owners to achieve required building certifications.

To learn more, contact us.

Aesthetically pleasing, cable railings offer an impressive installation option for a variety of commercial applications like rooftop decks, interior and exterior stairways, and stadiums where unobstructive views are ideal. Before installing cable railing, however, it’s important to understand how to install cable railing and the recommended framework for a successful and long-lasting installation.

Ideal Metal Frame Variations for Cable Railing

Metal frames and cable railing components, typically constructed using carbon steel or stainless steel, are commonly used in commercial applications for both interior and exterior. While carbon steel or stainless steel are the most common metal frame materials, other can be used. They need to be engineered to meet code requirements and other necessary considerations in the design of a sound cable railing system.

Carbon steel or stainless steel are recommended frames and cable railing components for commercial use because of their outstanding performance in use with cables. In choosing between carbon or stainless steel, it’s important to note the differences to determine what is best to use for your project.

Stainless Steel

Generally preferred for its corrosion resistance and low maintenance, stainless steel is specified typically for its aesthetic appeal for classic and modern designs. It is also resistant to high and low temperatures in most grades while maintaining its strength.

Carbon Steel

Harder and stronger than stainless, carbon steel is an excellent choice for more industrial use where appearance is not an issue. It is subject to corrosion if not coated and can tarnish or rust if not applied regularly. Carbon steel is  ideal for hidden areas and for cost-conscious projects.

Metal Railing Framing Construction

Properly tensioned cables will exert 225 pounds of tension each. A properly constructed metal framing and sturdy top rail is critical to prevent the end posts from bowing when the cables are tensioned. Three metal frame variations we recommend include:

Double End Post Construction 

double end post construction

This type of construction is strong, yet its elements are thin enough to have minimal visual obstruction created by the frame. This railing style uses an end post and two vertical members separated by stainless steel spacers. Intermediate posts are only one-inch thick, contributing to a seamless design.

Wall Structural Steel End Post Construction

End posts are slightly thicker for wall mounting; the intermediate posts can be smaller to minimize the frame’s bulkiness.

Pipe and Round Steel Tube Posts

Round tube used with a wall thickness at least comparable to schedule 80 or heavier pipe, or ¼-inch tube wall thickness. Top and bottom rails and intermediate posts constructed from schedule 40 pipe, or a minimum of 1/8-inch tube wall thickness.

Cable Railing Components

We recommend stainless steel cable railing components for exterior applications due to their low maintenance and longevity in extreme and fluctuating temperatures.

Stainless Steel Cable Brace

Since cable runs between terminating end posts can be quite long, it’s necessary to support the cable with intermediate posts or cable braces every 48-inches or less to prevent cable flexing beyond a 4-inch opening between cables (needed per the 4-inch sphere rule for guards). Cable braces come in two lengths, 36- or 42-inch, are ¼-inch by 1-inch and must weld to metal frames.

Stainless Steel Cable Brace Floor Plates

Used for mounting cable braces to the top or bottom rail or deck.

Stainless Steel Spacers

Stainless steel spacers, round, 1-inch in length, and are used to support thin-walled double end post design or allow for receiver extension in a stair system.

Detailed and downloadable drawings and material specifications are available.

Looking for information on how you can add cable railings to your project? View our inspiration or our products pages to learn more.