Negative Thermal Expansion.
Positive Results. ALLVAR Alloys.

Negative Thermal Expansion. Positive Results.

ALLVAR Alloys compensate for the thermal expansion of other materials.
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Tuneable CTE

Want zero CTE? No problem. Tune CTE for your design with ALLVAR Alloy's ultra-stable struts.
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Reduce SWAP-C

Improve unreliable optical performance and bulky designs with ALLVAR Alloys NTE spacers for Optics.
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Tackle CTE Mistmatch

ALLVAR Constant Force Washers maintain preloads across temperature changes.
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Negative Thermal Expansion Constant-Force Washers

Negative Thermal Expansion Commercially-Off-The-Shelf (COTS) Washers now available! 

ALLVAR Alloy washers and spacers combat other materials’ thermal displacement to keep constant force loads – whether it’s 80°C or -150°C. Athermalization of fastened assemblies can be achieved by eliminating the thermal changes in clamping force induced by different materials’ CTEs.

ALLVAR Alloy 30 SM1 Lens Tubes

Ready to breadboard your athermal optic design with ALLVAR?

ALLVAR Alloy 30 SM1 Lens Tubes make athermalization easier. Learn how negative CTE ALLVAR Alloy 30 lens tubes can help you create the exact CTE needed for your design here.

Custom Components of ALLVAR Alloy 30

Want to get your hand on ALLVAR Alloy 30 without the hassle of machining titanium? We can help.

Components made of ALLVAR Alloys can be custom-made for your application. Contact us early in the design cycle to learn how negative CTE will athermalize your design.

Component CTE Mismatch
SWaP-C Challenges
Fastener Slip
Optical Tolerancing
CTE Control
Fastener Fatigue
Maintaining Performance at Temperature
Narrow Safety Margins
Fastener Loosening


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Passive Athermalization made easy with Negative Thermal Expansion.

The process of removing thermal effects from a system is called athermalization. Creating an athermal design that actively athermalizes a system is challenging, and often increases the weight and complexity of a system. Passive athermalization achieves the same results as an active system, but without using powered systems or requiring outside feedback. It requires iterative changes and tweaks to hone the thermal changes of individual components in a design, so that they together work in unison to passively counteract thermal effects. These systems are challenging to design, manufacture, and test. ALLVAR Alloys makes this process much easier.

Tailored Thermal Expansion.

Negative thermal expansion ALLVAR Alloys allow engineers and designers to target a specific thermal expansion for their system. Designers select a specific thermal expansion, from –30 ppm/°C to a joined materials positive coefficient of thermal expansion, and incorporate a calculated length of ALLVAR Alloy 30 to hone in on a target CTE. Being able to tailor a specific CTE flips the design paradigm on its head. 

Blog & News



Video Resources - Learn More About ALLVAR and Negative Thermal Expansion

Click the images below to get our selection of videos and learn more about our company, our technology and our products.

ALLVAR University

Watch our videos to learn more about negative CTE and how it can be precisely compensate positive CTE components in athermal assemblies.

Demonstration Videos

Our demonstration videos show how important a washer can be, and how a simple change in Optics can eliminate thermal focus shift.

Meet Our Team

Meet our team, from our founder to our engineers, and hear their perspective on their new negative CTE alloys.

Watch a Webinar

Interested in a longer lesson on negative CTE and ALLVAR Alloys? Watch our webinar to get the details.

ALLVAR SPIE Defense + Commercial Sensing Banner Ad - Come see us at booth 518.. Negative Thermal Expansion Positive Results

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