Technical Details about Blasting and Coatings

Rust Grades & Blasting Classes

The level of abrasive blasting used is determined by the level of rust. NZ Industry standards for rust grade are as follows:

Grade A = Little if any rust present. Steel surface entirely covered in mill scale (flaky surface of hot rolled steel, consisting of iron oxides).

Grade B = Beginning of rust to steel surface and flaking/peeling of mill scale.

Grade C = Mill scale is rusted away or easily removable from steel surface. A little pitting is visible to surface.

Grade D = Considerable pitting visible and no mill scale present on steel surface.

C1—Light blast cleaning removing loose mill scale, rust and dirt.

C2—Commercial medium blast cleaning, stripping metal surface back to grey metal

C2.5—Near white blast intensity removes scale and rust to leave only traces. The steel surface is various shades of grey.

C3—Total white blast intensity entirely removing scale and rust and returning steel surface to uniform bare metal colour and some shading of grey.

Industry guidelines on intensity of abrasive blasting:​

Material Safety Data Sheets

To view the Material Data Safety Sheets for the products we use, please visit the suppliers websites.

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