![](https://cdn.austrian-standards.at/thumbnail/shop/Product_Icons/118162/image-thumb__118162__as_book_product_detail_preview/Icon_ISO.png)
![](https://cdn.austrian-standards.at/thumbnail/shop/Product_Icons/118162/image-thumb__118162__as_organization_pdp_logo/Icon_ISO.png)
ISO 11127-4:1993
Issue date: 1993 12 09
Preparation of steel substrates before application of paints and related products — Test methods for non-metallic blast-cleaning abrasives — Part 4: Assessment of hardness by a glass slide test
The procedure includes examining a small quantity of the sample under the microscope and, if grains of different colours or diameter are present, selecting a few grains of each, placing the selected grains between two glass microscope slides and, whilst applying pressure, slowly moving one slide over the other with a reciprocating motion for 10 s, examining the glass surfaces for scratches. The object of the method is to assess whether the sample has a minimum hardness of 6 on Mohs' scale. Annex A gives information on the international standards series for non-metallic blast-cleaning abrasives ISO 11126 and ISO 11127.