How to Select Spiral Tubes for Low Temperature Applications: A Complete Engineering Guide

はじめに

For EMI engineers, selecting a Spiral Tube for low temperature applications requires more than choosing a cold-resistant material. The key is maintaining stable electrical contact and shielding performance under extreme conditions, where factors such as thermal contraction, material compatibility, dimensional changes, compression variation, oxidation, and thermal cycling reliability can affect the entire shielding system. Since the Spiral Tube works together with the mounting groove and enclosure, engineers must ensure reliable contact is maintained throughout temperature changes.

1.Define the Actual Temperature Range Before Selecting a Spiral Tube

Low Temperature” Is Not a Single Design Condition，One of the most common mistakes in engineering projects is describing an application simply as “low temperature.”In reality, -40°C, -80°C, and -196°C represent completely different design challenges.The first step in Spiral Tube selection is to define the actual operating environment.

アプリケーション環境	標準温度範囲	Main Design Focus
Outdoor electronic equipment	Around -40°C	Contact stability, corrosion resistance
Industrial and semiconductor equipment	-60°C to -80°C	Thermal cycling, dimensional stability
Cryogenic systems	Below -100°C	Material behavior, thermal contraction
Liquid nitrogen environments	Around -196°C	Low-temperature verification, material compatibility

Before selecting a Spiral Tube, engineers should confirm:

For example:A device that occasionally operates at -40°C is very different from a semiconductor testing system that repeatedly cycles between:

25°C → -80°C → 25°C hundreds of times.The second application requires much more attention to:

• Material fatigue
• Relative thermal movement
• Contact stability after repeated cycling

2.Material Selection Guide for Low Temperature Spiral Tubes

For EMI shielding Spiral Tubes, commonly considered materials include:

• ベリリウム銅 (BeCu)
• ステンレス鋼
• 17-7PH

However, material selection should not simply follow the idea:“The higher the conductivity, the better the material.”The correct choice depends on the primary project requirement.A material with excellent conductivity may not always be the best solution if the application requires:

• High mechanical strength
• 耐食性
• Extreme temperature stability
• Long-term thermal cycling reliability

The following table provides a practical engineering comparison:

素材	Main Engineering Consideration	Typical Application Direction
BeCu	Electrical contact performance and mechanical flexibility	Applications requiring stable conductive contact
ステンレス鋼	Strength, corrosion resistance, cost efficiency	Industrial and harsh environments
17-7PH	High strength, fatigue resistance, corrosion resistance, and heat-treatability.	Highly demandAerospace, high-performance springs, seals, and high-stress components.
チタン合金	Lightweight and corrosion-resistant design	Special aerospace or advanced applications

Handa’s Spiral EMI Shielding products support multiple material options, including:

• ベリリウム銅
• ステンレス鋼
• Titanium Alloy
• Nickel-based alloys such as Inconel and Hastelloy for customized applications

Handa’s Spiral EMI Shielding products support multiple material options, including:

• ベリリウム銅
• ステンレス鋼
• Titanium Alloy
• Nickel-based alloys such as Inconel and Hastelloy for customized applications

More information can be found here:https://www.handashielding.com/emi-shielding-spira/

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3.Why BeCu Is Commonly Considered for EMI Spiral Tube Applications

Beryllium Copper (BeCu) is widely used in EMI shielding applications because it provides a balance between:

• 電気伝導度
• 機械的強度
• Spring-like recovery characteristics
• Long-term contact reliability

For EMI shielding structures, electrical conductivity is important because the shielding component must provide a continuous low-impedance electrical path.However, conductivity alone does not determine EMI performance.The actual shielding behavior also depends on:

• Contact condition
• 表面処理
• Installation geometry
• Compression level
• 周波数範囲

Therefore, the engineering evaluation should consider the complete structure rather than only the base material.

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4.Why Doesn’t “25% Compression” Automatically Mean 25% Compression at Low Temperature?

This is an important distinction in low-temperature applications.Suppose a Spiral Tube is installed at 25°C using the recommended dimensions and achieves the desired compression condition.As the temperature decreases:

• The Spiral Tube changes dimension.
• The housing changes dimension.
• The installation groove changes dimension.
• Different materials may experience different amounts of thermal contraction.

Therefore:

A 25% compression condition at room temperature does not automatically mean that exactly the same geometric compression condition will be maintained at low temperature.For demanding low-temperature applications, it is therefore useful to evaluate at least three conditions:

Condition	What Should Be Checked?
Room-temperature assembly	Initial compression, installation force, contact condition
Minimum temperature	Actual compression condition and electrical contact continuity
After thermal cycling	Permanent deformation, wear, and changes in contact condition

The third condition is particularly important for equipment intended for long-term operation.A design may perform well during the first cooling cycle but experience changes in contact behavior after dozens or hundreds of thermal cycles.

Have questions about low-temperature Spiral Tube selection? Feel free to contact our engineers for technical advice and a suitable solution for your application.

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5.Surface Treatment: Don’t Choose a Plating Only Because It Has the Highest Conductivity

Spiral Tubes may use surface treatments to improve contact performance, environmental resistance, corrosion resistance, or material compatibility.Depending on the product configuration, Handa can provide surface treatments including:

• 錫
• ニッケル
• シルバー
• ゴールド
• 不動態化
• 亜鉛

However, it would be overly simplistic to say:”Gold is the best, so gold should always be selected for low-temperature applications.”

In actual engineering design, the following factors should be considered together:“Base Material + Plating + Mating Material + Environment + Contact Requirement + Cost”，For some applications, the primary purpose of the surface treatment may be to improve resistance to oxidation or maintain stable electrical contact.For other applications, long-term environmental durability may be the more important consideration.Therefore, surface treatment should be evaluated as part of the overall electrical contact system rather than as an isolated parameter.

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6.What Is Different About Selecting Spiral Tubes for -40°C, -80°C, and -196°C?

Low-temperature applications can be broadly divided into several engineering levels.

Temperature Scenario	Main Risk	Selection Focus	Recommended Validation
Around -40°C	Low-temperature contraction and contact changes	Material + compression + groove dimensions	Low-temperature hold / cycling
Around -80°C	More significant thermal movement	Material compatibility + structural dimensions	Thermal cycling + contact testing
≤ -100°C	Deep-low-temperature dimensional changes	Temperature-dependent material data + structural analysis	Low-temperature testing
Around -196°C	Cryogenic conditions	Material condition, thermal contraction, structural reliability	Actual cryogenic validation

There is no simple rule that says:”-80°C always requires Material A, while -196°C always requires Material B.”

The actual design depends on:

• Spiral Tube dimensions
• Material condition
• Housing material
• 溝のデザイン
• 圧縮
• Number of thermal cycles
• Acceptable contact variation

A more accurate engineering approach is therefore:Temperature → Material → Relative Movement → Compression → Validation rather than:温度 →Material

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7.Don’t Directly Apply Room-Temperature EMI Test Data to Low-Temperature Applications

Room-temperature EMI test data should not be directly applied to low-temperature applications.For example, if a Spiral Tube achieves a specific shielding effectiveness at 25°C, you should not claim the same performance at -80°C unless low-temperature test data is available.This is because low temperatures may affect material properties, electrical contact, and overall assembly continuity, which can influence shielding performance.

For applications requiring verified low-temperature EMI performance, testing may include:

Room-Temperature Test → Controlled Cooling → Minimum Temperature Hold → Low-Temperature Contact Check → Controlled Heating → Thermal Cycling → Post-Cycle EMI Test

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8.What Information Should You Provide for an Actual Engineering Project?

If you are sourcing a Spiral Tube for semiconductor equipment, vacuum equipment, low-temperature electronics, or another demanding application, providing the following information at the beginning of the project can significantly improve the accuracy of the recommendation.

Temperature Conditions Mechanical Structure

Materials Environmental Conditions

The more complete these parameters are, the more accurately the material, dimensions, and surface treatment can be evaluated.

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9.How Can Handa Help You Select the Right Low-Temperature Spiral Tube?

For low-temperature and cryogenic applications, Spiral Tube selection should consider temperature, material, mechanical structure, and compression together—not just dimensions.Handa offers Spiral Shield solutions with different materials, tube diameters, compression conditions, and surface treatments. Customized designs are also available based on drawings and application requirements.

To recommend a suitable configuration, provide:Temperature + Housing Material + Groove Size + Spiral Tube OD + EMI Requirement。These parameters help determine the appropriate material, structure, and compression configuration for your application.

If you still have questions, please contact our engineers.