NITAL ETCH TEST

What is Nital?

Nital is a mixture of nitric acid and alcohol commonly used for etching carbon steels. The name derives from these two main components. Nital is a named formula listed in ASTM Standard E407 and is alternatively known as ‘nitol’ or ‘nytal’. It is important to know that nitric acid is a strong oxidizer, and alcohol is a fuel. The process of mixing these two components can be potentially dangerous without the proper knowledge or equipment. Our pre-mixed, ready-to-use Nital products are made with methanol. They are very stable and not liable to explosion. For safety reasons, we do not sell any Nital mixture stronger than 5%, such as 10% Nital.

What is Nital Etch Test?

Nital Etch Test is a procedure for checking machining damage or grinding burn of a hardened steel component. It is also referred to as the Temper etch test, Nital inspection test, Nital NDT, MIL-STD-867C, AMS 2649C, and more. Machining or grinding processes can generate a significant amount of heat in a steel component. If a specific area is not adequately cooled, it may overheat, leading to undesirable changes in the steel’s properties. Even if there are no visible burn marks, an overheated area (over-tempered area) 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 sell 2% and 3% Nital solutions for metallographic applications.