Reliable and Precise.

Invar is at the core of Re-Steel Supply Company’s business. Our product portfolio includes Invar 36 and Invar 42 for fabricating composite tooling and applications where dimensional changes due to temperature variation must be minimized.

Re-Steel Supply Company produces common sizes of Invar plate, and stocks plate to fill custom orders as needed.  Re-Steel’s products are tough – and precise and our Invar 36 and Invar 42 are manufactured in the highest accordance set forth by the aerospace industry.

Why Invar?

Invar is a common term for nickel iron alloys, more specifically alloys with a nickel content of around 36% and the nickel iron alloy has a very low coefficient of thermal expansion.

INVAR HAS BEEN USED FOR SCIENTIFIC AND ENGINEERING PURPOSES FOR ALMOST 100 YEARS
The alloy was invented in 1896 by Swiss physicist, Charles Edouard Guillaume. He discovered it while looking for an alternative to the costly platinum iridium that was being used for a standard of metric measurement at the time. The nickel iron alloy was deemed a successful alternative.

The alloy was named Invar after the invariable effect, referring to the alloys lack of expansion or contraction with temperature changes – a characteristic that makes it very applicable for composite tooling. Tooling materials must provide temperature resistance, very low CTE to match the composite, vacuum integrity, thermal conductivity and machinabillity. Invar has become a choice material amongst factory management and toolmakers and other advantages of the specialty alloy include:

ADVANTAGES OF METALLIC TOOLING
⎯    Malleable and adjustable
⎯    Extreme durability and longevity
⎯    Maintains pressure and vacuum integrity, no micro-cracking or leakage
⎯    Damage tolerant, glass and carbon fiber composites are fragile with a lower surface hardness
⎯    Lowest coefficientsof thermal expansion and thermal conductivity of metallic tooling materials

Below is a chart that details the variances between metals used for composite tooling.

As the aerospace industry has evolved in their manufacturing materials from aluminum to carbon fiber, Invar has taken a lead within the composite structured industry. Most important to the tools designer is what materials to use to manufacture a part. If you need a specific heat up rate, then you want to pay close attention to the thermal mass. When choosing a mold material or secondary fixture, you want to pay close attention to how much it will change dimensionally at a given temperature. Invar changes the least. With Invar’s near zero coefficient of thermal expansion, Invar is ideal for constructing precision instruments whose dimensions need to remain constant in spite of varying temperature.