What is Nital?

Nital is a mixture of nitric acid and alcohol commonly used for etching carbon steels. The name derives from these two ingredients. Nital is a named formula listed in ASTM Standard E407. This mixture is also known as “nitol” or “nytal”. It is important to know that nitric acid is a strong oxidizer, and alcohol is a fuel. Mixing them together can be potentially dangerous if you don’t have the proper knowledge or equipment to do so. Our pre-mixed, ready-to-use Nital solutions are made with methanol, they are very stable and not liable to explosion. We do not sell any Nital mixture stronger than 5% (such as 10% Nital) for safety reasons.

What is Nital Etch Test?

Nital Etch Test is a procedure for checking machining damage or grinding burn of a hardened steel component. It’s also known as the Temper etch test, Nital inspection test, Nital NDT, MIL-STD-867C, AMS 2649C, etc. Machining or grinding can introduce a tremendous amount of heat into a steel component. If an area of the component is not cooled properly by a water jet, it will overheat. This can produce undesirable changes in the steel’s properties. An overheated area (over-tempered area); may not have any visible burn marks, but it can be identified using the Nital etch test. The overheated area will appear in a different color than the surroundings after the test.

  • A typical Nital etch test procedure for low-alloy steel parts is here.
  • Nital etch test is a non-destructive surface test, NOT a weld penetration test. For welding related products, please go to this page.

Our Nital etch test products are below:

  • 5% Nital solution.
  • Hydrochloric acid solution, for de-smutting.
  • Acid neutralizer, for neutralizing acidic residuals on the sample’s surface.
  • Nital test kit (contains the above 3).
  • Lab tongs, PTFE coated, for dipping the sample into acids.
  • We also have 2% and 3% Nital solutions for metallographic applications.