A cracked rubber vibration mount can turn a minor maintenance issue into an unexpected shutdown.

In outdoor telecom cabinets, vehicle-mounted electronics and shipboard equipment, elastomer components are repeatedly exposed to temperature cycling, oil, moisture, ozone and continuous mechanical stress. As the rubber hardens or develops surface cracks, its stiffness changes. The isolation system may then transmit more vibration than the original design allowed, even though the mount still appears to be in place.

This does not mean rubber isolators are unsuitable for every application. They remain practical for many indoor machines and cost-sensitive installations. The problem begins when a standard elastomer mount is used in an environment that exceeds its material or service-life limits.

For equipment exposed to combined vibration, shock and environmental stress, engineers are increasingly evaluating all-metal wire rope isolators as an alternative.

How an All-Metal Wire Rope Isolator Controls Vibration

A wire rope isolator normally consists of stranded stainless steel cable held between two metal retaining bars. Common HOAN configurations use 304 stainless steel wire rope with machined 6061-T6 aluminum alloy retainers, although materials can be adjusted for specific operating conditions.

Its damping does not depend on a bonded rubber element or hydraulic fluid. When the isolator deflects, individual wires within the rope move against one another. The resulting friction dissipates part of the vibration and shock energy as heat.

This construction produces a non-linear load-deflection response. Under normal vibration, the isolator provides the flexibility required to reduce force transmission. During a higher shock input, its stiffness increases progressively, helping restrict excessive displacement.

For selected HOAN isolators, the resonance amplification factor can be controlled to approximately 3.5 or below, while some product configurations specify a limit of 4 or below. The actual value depends on the model, supported mass, installation direction and excitation conditions. It should therefore be confirmed using the product’s dynamic curve rather than treated as a universal value.

All-Metal vs Rubber or Elastomer Vibration Mounts

The table should not be read as a claim that one technology is always superior. Selection must be based on equipment mass, center of gravity, disturbing frequency, available displacement, installation orientation and environmental exposure.

Why Material Selection Matters

The term “all-metal isolator” does not automatically guarantee reliable performance.

The wire rope grade affects corrosion resistance, fatigue life and strand friction. The retainer material and clamping process determine whether the rope remains securely fixed during repeated loading. Hole position, rope diameter and loop geometry also affect stiffness in the compression, shear and roll directions.

For outdoor or marine equipment, engineers should confirm whether the selected materials are appropriate for humidity, salt spray and chemical exposure. For high- or low-temperature applications, the complete isolator assembly—not only the stainless steel cable—must be evaluated.

HOAN manufactures multiple wire rope isolator configurations and uses vibration and shock test benches as part of its product inspection process. Product acceptance requirements can also be defined through technical agreements according to the customer’s operating conditions.

Which Vibration and Shock Standards Should Be Considered?

Testing should reproduce the actual service environment as closely as possible. A standard number alone does not prove that an isolator is suitable; the frequency range, acceleration level, duration, mounting condition and supported mass must also be specified.

Common references include:

MIL-STD-810H

MIL-STD-810H provides environmental engineering guidance and laboratory test methods for equipment exposed to conditions such as vibration and mechanical shock. Engineers frequently refer to Method 514.8 for vibration and Method 516.8 for shock, but the test profile must be tailored to the equipment’s lifecycle rather than copied without analysis.

Official resource:U.S. DLA ASSIST Quick Search

IEC 60068-2-6:2007

IEC 60068-2-6 defines a standardized sinusoidal vibration test procedure used to identify mechanical weakness, performance degradation and dynamic behavior. The IEC lists the 2007 edition as valid, with a stability date of 2029.

Official resource:IEC 60068-2-6:2007

ISO 20816-1:2016

ISO 20816-1 provides general guidance for measuring and evaluating machine vibration. It is useful when defining operating vibration limits and evaluating whether vibration could affect long-term machine reliability. The 2016 edition remains published, although ISO is preparing a replacement edition.

Official resource:ISO 20816-1:2016

How HOAN Approaches Isolator Selection

Selecting an isolator from load capacity alone is risky. Two cabinets with the same total mass may require different solutions because their centers of gravity, mounting points and input frequencies are different.

HOAN begins selection by reviewing:

· Equipment mass and load distribution

· Number and position of mounting points

· Vibration frequency and acceleration

· Shock pulse, peak acceleration and duration

· Maximum allowable displacement

· Installation direction

· Temperature and corrosion conditions

The engineering team then checks the load-deflection and dynamic performance curves for the proposed model. Where necessary, vibration, shock or environmental verification can be agreed before production.

Choosing for Service Life, Not Only Unit Price

Rubber mounts remain a sensible option when the environment is controlled and replacement is easy. All-metal wire rope isolators become more attractive when equipment must withstand repeated shock, temperature variation, corrosion or long periods without maintenance.

The correct decision is not “metal versus rubber” in isolation. It is whether the selected mount can maintain the required stiffness, damping and structural integrity throughout the equipment’s intended service life.

For telecom cabinets, shipboard electronics, UAV payloads, vehicle-mounted instruments and other demanding systems, HOAN can evaluate the operating data and recommend a suitable wire rope isolator, shock isolator or customized vibration-control arrangement.