Invar 36 by Other Names: Regional Trade Names and Specs
“Invar” is a trademark that became the generic name for the alloy family, and different mills across different regions have sold essentially the same 36 percent nickel-iron composition under their own trade names for decades. For a buyer working with suppliers in more than one country, or inheriting a drawing written against an unfamiliar spec, knowing these names refer to the same material saves a confusing conversation.
Where the name “Invar” comes from
Invar was originally a trademark, from the French “invariable,” registered by the alloy’s early 20th century developer. Over time it became the common generic term for iron-nickel alloys in this composition family, similar to how some trademarks become the everyday name for a category of product. Today “Invar 36” most often refers to the composition and performance defined by specifications like ASTM F1684, regardless of which mill actually produced the material.
Common regional and supplier trade names
| Name | Typical origin | Notes |
|---|---|---|
| Invar 36 | International, most common in US/UK usage | Tied to ASTM F1684 |
| Pernifer 36 | Germany | Common in European supply chains |
| Nilo 36 | UK | Historical trade name, still referenced on older drawings |
| Vacodil 36 | Germany | Another European trade name |
| FeNi36 | Europe, generic | Descriptive composition-based designation rather than a brand |
| Invar Steel | Informal, various | Colloquial usage, not a distinct spec |
These are not exhaustive, and mills occasionally use additional local designations. The underlying point holds across all of them: they describe the same roughly 36 percent nickel, balance iron composition with closely comparable low-expansion behavior, not different materials.
Why this matters for buyers
Comparing international quotes. If you are sourcing from shops in the US, Germany, Japan or elsewhere, a quote referencing Pernifer 36 or Nilo 36 instead of “Invar 36” is very likely quoting equivalent material, not something different or inferior. Confirming the governing specification, most often traceable back to ASTM F1684 or an equivalent regional standard, is more useful than treating the trade name mismatch as a red flag.
Inherited or legacy drawings. Programs that have run for years, particularly in aerospace and defense, sometimes carry drawings written against an older or regional trade name. A new shop unfamiliar with that specific name may ask for clarification, which is a reasonable question, not a sign they lack Invar experience, covered more broadly in how to find a machine shop with real Invar experience.
Material certification cross-referencing. When a mill certificate references a trade name rather than “Invar 36,” check that the certified chemistry falls within the composition range your governing specification requires, discussed further in Invar material certification, rather than rejecting the cert on the trade name alone.
What to do when the names do not match
If a drawing or supplier reference does not match what your current shop calls the material, the practical fix is to compare compositions and governing specifications, not names. Ask for the chemistry range and the ASTM or equivalent standard the material is certified to, and confirm it falls within what your drawing actually requires. In most cases the material is equivalent and the naming difference is purely regional convention.
Specifying clearly on new drawings
For new designs, specifying “Invar 36, ASTM F1684” rather than a regional trade name alone gives any shop, anywhere, an unambiguous reference regardless of what they call the material locally. This is one of the details covered in what to include on an Invar RFQ.
Getting a quote regardless of naming
If you are working from an older drawing or a spec you are not sure how to translate, describe the composition and application on your RFQ rather than only the trade name, and we match you with shops that can confirm equivalence before quoting.
Send your drawing through our RFQ form, and we match you with up to three shops that source and machine this alloy family regardless of which regional name your paperwork uses.
Frequently asked questions
Are Pernifer 36 and Nilo 36 the same material as Invar 36?
They are the same base 36 percent nickel-iron composition sold under different trade names by different producers, historically tied to specific mills or regions. In practice they are treated as equivalent for most engineering purposes, but a program with strict material pedigree requirements should confirm the specific spec and mill, not just the trade name.
Why does this matter if I am buying finished machined parts, not raw material?
It mainly matters when comparing quotes or specs across suppliers in different countries, or when a drawing inherited from an older program references a name your current shop does not recognize. Knowing the names are equivalent avoids a confusing back-and-forth over what looks like a different material.
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