Negative CTE ALLVAR round bar and tube

Currently, we are able to offer our Negative Expansion Alloys in bar (up to 2.25” round) and tube (up to 3.00” OD) depending on wall thickness. These can be supplies as semi-finished pre-forms or as a machined part for use in struts.

We also offer thermal compensating washers and spacers to maintain constant pre-loads to control the margin of safety of bolted joints. These negative thermal expansion washers and spacers are available as Type B washers and in custom sizes.

Not sure if our material is the right fit for your project? We would be happy to discuss the usage of negative thermal expansion materials as it relates to your project.

Negative Coefficient of Thermal Expansion Washers

Negative CTE washers and spacers from ALLVAR compensate for the natural expansion and contraction of other materials with variations in temperature. ALLVAR washers/spacers combat other materials' thermal displacement to keep constant force loads - no matter if it's 80°C or -150°C. Athermalization of fastened assemblies can be achieved by eliminating the thermal stress induced by different materials.


Kit includes:
• 12 hours of design and engineering time from Allvar engineers
• Set of washers (quantity depends on size of washers and the application)

Washers available in #2, #4, #6, and #8 sizes. Custom washer and spacer sizes are available 

Type B Regular Plain Washers

Nominal Washer Size Washer Inside Diamter Washer Outside Diameter Thickness Range Washer Standards ASME B18.24 Part Number Item Number
2 0.094" 0.250" 0.028" - 0.036" ASME B18.22.1 AEW26X08R000GY0A1 AW30-0002 Contact for pricing
4 0.125" 0.375" 0.036" - 0.045" ASME B18.22.1 AEW26X11R000GY0A1 AW30-0004 Contact for pricing
6 0.156" 0.438" 0.036" - 0.045" ASME B18.22.1 AEW26X13R000GY0A1 AW30-0006 Contact for pricing
8 0.188" 0.500" 0.036" - 0.045" ASME B18.22.1 AEW26X16R000GY0A1 AW30-0008 Contact for pricing