Scaffolding Tube Coating Guide

First identify whether the tube was formed from pre-coated material or coated after manufacture. Obtain the applicable coating specification, substrate conditions, measuring method, locations and sampling rules. State which requirement applies to an individual reading and which applies to a local/mean result or lot.

For a confirmed single-reading lower bound L, the tool compares measured thickness m ≥ L and the interval m ± entered expanded uncertainty with L. It does not calculate uncertainty or choose a conformity decision rule. Zero uncertainty models numerical comparison only. No zinc mass-to-thickness conversion, mean/local sampling rule or expected life calculation is performed.

Assume the buyer has an illustrative single-reading lower bound of 50 µm. A reading of 60 µm with expanded uncertainty 5 µm gives an interval of 55–65 µm, wholly above that bound. A reading of 52 µm with uncertainty 5 µm gives 47–57 µm, overlapping it.

These values are not a recommended scaffold coating or a standard minimum. If the actual 50 µm criterion applies to a mean rather than this reading, select unresolved: the result is “Not comparable”. Confirm the correct method and sampling with the reviewer before accepting the delivered lot.

AGA distinguishes galvanizing fabricated articles from continuously coated sheet.

Buyer implication: State the actual route, coverage and inspection basis for the tube.

Method: Review of the primary publisher’s public scope or guidance; procurement implications are editorial analysis. Applicability: Process distinction relevant to coated tube purchasing. Limit: No thickness minimum, seam/end treatment, repair approval or service life is selected.

American Galvanizers Association FAQ · Information reviewed 16 October 2026.