How to Choose the Right Cable Ties for Wiring Harness?

With the increasing use of electrical and electronic components and subsystems, properly securing cables is an important aspect of system design that is often overlooked. Whether within equipment or between systems, ensuring that cables are routed safely, securely and efficiently is critical to the success and longevity of a design, especially in high-vibration and harsh-environment applications. This article’s wiring harness engineer mainly introduces how to select and apply the correct cable ties for wiring harnesses.
The challenge for designers is to find cable ties that meet application needs in terms of tensile strength, longevity, flexibility, chemical, vibration and ultraviolet (UV) radiation resistance. without over-engineering or compromising the integrity of the cable’s insulation and internal structure. This requires analyzing the many types of cable ties and various materials now available and differentiating them, fearing that choosing the wrong cable tie could end up costing much more than the purchase.
To alleviate these concerns, designers need to understand the nuances of cable ties and how to align their selection with application requirements. This article will outline the considerations for cable ties, the advantages of each type, and how to apply them effectively using real-life examples from Panduit Corporation.

Choose secure cable ties

Tie specifications
Cable ties, often called zip-ties or tie wraps, are available in a variety of lengths, widths, materials, and colors. When bundling a wire bundle, the tie or tape portion should be wrapped around the wire bundle, pulling the loose end completely through the locking mechanism and tightening until the strap locking notch is securely engaged (Figure 1).

SGM100M-M0 cable tie

Figure 1: A typical cable tie showing the main components used to secure a cable bundle.
The cable tie may be constructed as a single piece with the locking barbs molded as part of the locking mechanism. In contrast, higher quality ties have a two-piece construction. In the two-piece design, corrosion-resistant stainless steel barbs are embedded into the lock head to grip the relatively smooth lacing surface. It is designed to provide a secure lock that is infinitely adjustable, as the barbs do not need to fit into the locking grooves.
The maximum diameter specification indicates the largest diameter wire bundle that the tie can accommodate. The bundling should be securely fastened without over-tightening and cutting or abrading the cable insulation. The length of tie used should allow for an extra point to engage the loose end in the locking mechanism.
The strength of a wrap is defined as the loop tensile strength (LTS) measured in pounds. LTS is the maximum force that can be exerted when the locking mechanism is engaged. The most common ties are between 18 pounds and 250 pounds.
LTS depends on the size of the tie and the material used. Material selection is primarily influenced by the environmental operating conditions the tie will experience. Considerations include:
Is it for internal or external use?
What is the expected temperature range?
Will it be exposed to water, oil, chemicals or vibration?
For example, Panduit’s PLT1.5M-M10 cable ties are part of the company’s PAN-TY@PLT series of ties. This line of cable ties is its largest and most comprehensive range, offering ties in a variety of colors, materials and construction types. The PLT1.M-M10 has a nominal length of 5.6 inches (inches), a rated maximum diameter of 1.25 inches, and a tensile strength of 18 pounds. Frenulas are classified by their cross-sectional area as extra-small, micro, or intermediate. The PLT1.M-M10 is a miniature tie with a one-piece construction design. It is made of nylon 6.6 and is suitable for indoor use.
As mentioned earlier, another common cable tie design consists of two pieces with a separate stainless steel barb that replaces the molded nylon barb in the one-piece design (Figure 2).

ERT2M-C20 elastic cable tie

Figure 2: Single-piece fabrication with molded locking barbs (a) shown along with two-piece fabrication (b) using stainless steel barbs inserted after forming.
The aqua cable tie shown on the left in Figure 2 is one of the variants of Panduit’s PLT3S-C76 — PAN-TY@PLT series. It is made from ethylene tetrafluoroethylene (ETFE) and is suitable for applications requiring chemical resistance, flame retardancy and radiation resistance. The cable tie on the right in Figure 2 is Panduit’s BT4S-M0, a member of the DOME-TOP BARB-TY BT series, manufactured with individual barbs. Additionally, this series of ties features rounded heads and rounded edges to minimize wear on the wire insulation. The black color is achieved by adding carbon black to the nylon, which improves resistance to UV rays, making this color more commonly used in outdoor applications.
Cable ties are manufactured from a range of materials specific to the environment in which they are intended to be used. The basic lacing is molded from nylon 6.6. Nylon 6.6 offers high mechanical strength, stiffness, good heat resistance and reasonable chemical resistance. Variants include weather-resistant, heat-stable and flame-retardant nylon 6.6.
Various other materials are used to achieve specific tolerances. For example, the DT8EH-Q0 is designed for high strength as well as resistance to impact, chemicals, UV rays and weather. It uses acetal (polyoxymethylene, or POM), a range of materials including Delrin. It is 2.25 feet (ft.) long and has a tensile strength of 250 pounds. These cable ties are designed for harsh outdoor applications in the power and communications industries.

SST1.51-M cable tie strap locked on toothed wedge

temperature range
The temperature range that a cable tie can withstand depends primarily on the materials used in its construction. Nylon 6.6 is rated for an operating temperature range of -76°F to +185°F. Heat-stable nylon 6.6 extends the upper end of the range to 212°F. PEEK has the highest temperature tolerance, with an upper temperature limit of 500°F.

special function
The Panduit CBR1M-M, part of the Contour-Ty Series, features a unique design that prevents damage to wire insulation or cable jacketing. It features a low-profile head design that uses parallel inlets to limit exposure of sharp edges and reduce snags, and features locking indentations on the outside of the strap (Figure 3).

HV9150-C0 cable tie with in-line design

Figure 3: The Contour-Ty Series uses a locking mechanism that is set at right angles to the strap section for parallel insertion and locks notches on the outside to prevent damage to the insulation.
HV9150-C0 push-in cable ties are made from weather-resistant nylon 6.6. Mechanically, it adopts a double-wedge design locking mechanism to achieve fixed locking and flexible locking (Figure 4).

Contour-Ty Series Locking Mechanism Cable Ties

Figure 4: The HV9150-C0 features an in-line design that allows parallel access to the locking mechanism to reduce the height of the cable bundle.
The releasable head allows for temporary binding before final locking. Indentations are molded into both sides of the strap, providing extra locking strength and greater flexibility. It has a length of 1.721 feet, a beam diameter of 5.92 inches, and a tensile strength of 160 pounds.
SST1.51-M cable ties are 5.3 inches long and have a tensile strength of 40 pounds (Figure 5). It is designed with a small head height for general bundling and through-panel applications. Its two-piece design has what Panduit claims is the lowest stringing force in the industry and is 14% lighter than a one-piece design. Additionally, the straps are releasable before final tightening.

Cable ties with molded locking barbs

Figure 5: The SST1.51-M two-piece design uses a floating ring to lock the strap to a toothed wedge. The ties can be loosened by pulling the collar back and bending the wedge away from the straps before final locking.
Where most cable ties have low stretch capabilities, the body of the Panduit ERT2M-C20 is designed to be flexible (Figure 6).
Figure 6: ERT2M-C20 elastic cable ties feature flexible straps that prevent over-tightening.
This type of zip tie is designed to conform to a bundle of wires or fiber optic cables to prevent over-tightening. It also has a high coefficient of friction that grips wires to prevent lateral movement. This removable cable tie is 8.5 inches long and has a tensile strength of 18 pounds. Like other ties in the range, it has a UL94V-0 flame retardant rating – meeting strict telecommunications flammability requirements – and is halogen-free and non-toxic.
The SG100M-M0 is suitable for use in maintenance, repair and overhaul environments as well as rough installation practices in the construction industry (Figure 7).
Figure 7: The SGM100M-M0 cable tie features a low mounting head height, flared neck, and tapered tip for easy threading.
It’s made from weather-resistant nylon 6.6, making it ideal for applications subject to intense UV exposure. It is 4.2 inches long and has a tensile strength rating of 18 pounds. Its thin, wide straps are designed to flexibly grip cable bundles and reduce lateral wire movement.

in conclusion
Although cable ties are often considered relatively simple, designers need to carefully consider the many available options to ensure the most appropriate tie is used for the application. As shown, cable ties are available in lengths from inches to several feet, are compatible with a variety of environments, and have many features to meet the needs of a variety of applications.