Compare both values separately with the application specification.
Understand chemistry
How to interpret trace elements in high-purity aluminium
A purity label such as 3N8 or 4N summarises aluminium content. Technical suitability also depends on how the remaining fraction is distributed across the elements that matter to the buyer.
Technical editorial: HUABO Advanced Aluminium · Updated
Even small values may affect project-specific acceptance criteria.
Do not infer it from total purity; review the analytical result.
The N-grade does not replace a list of critical maximum limits.
01
Total purity and element profile are two checks
3N2, 3N5, 3N8, and 4N identify minimum aluminium-content levels. Two batches within the same N-grade can still distribute the remaining fraction differently across individual elements.
State a maximum for every acceptance-critical element alongside minimum aluminium content. Whether Si, Fe, Cu, Mn, Mg, Zn, or Ga is critical depends on the application and the buyer’s acceptance specification.
02
Normalise units before comparing results
Analytical data may be reported in weight percent or ppm. One weight percent equals 10,000 ppm, so 0.001 weight percent equals 10 ppm. Comparing figures without a common unit invites error.
State the unit for every limit in the RFQ. Where relevant to approval, also clarify whether aluminium is measured directly or calculated by difference.
03
Read zero values, rounding, and reporting limits carefully
A displayed zero does not necessarily mean that an element is physically absent. Depending on the report, it may reflect rounding, display convention, or a result below the reporting limit.
For critical elements, request the test method and a suitable reporting limit. Clarify ambiguous notation with the supplier before release rather than waiting until incoming inspection.
04
Check typical data against the actual batch CoA
HUABO publishes typical batch data for Al, Si, Fe, Cu, Mn, Mg, Zn, and Ga. It supports technical screening but does not guarantee a future delivery.
The agreed purchase specification and the CoA for the actual batch govern acceptance. Before ordering, define which elements, units, methods, and batch references the report must include.
Related resources
Continue the technical review
Read a Certificate of Analysis
Review batch identity, units, method, and acceptance specification together.
Open resource3N8 product data
Typical 3N8 batch data and project-specific inquiry information.
Open resource4N product data
Typical 4N batch data and context for a 4N5 project target.
Open resourceFAQ
Short answers for procurement and engineering
Is 99.99% aluminium enough to select material?
Not always. Add application-critical maximum limits, units, test method, and reporting limit.
How do weight percent and ppm convert?
One weight percent equals 10,000 ppm. Therefore, 0.001 weight percent equals 10 ppm.
Are published typical values guaranteed delivery limits?
No. They provide context; the agreed specification and actual batch CoA govern acceptance.
RFQ
Send a reviewable inquiry
State grade or target chemistry, form, total quantity, application, documents, destination, and timing. Commercial terms are confirmed after review.