A number of often-used perforated plate sieves with round and square apertures cannot be found in any of the conventional standards like ISO 3310 or ISO 5223 and their ASTM equivalents. It therefore arises a need for unified quality requirements under which these sieves can be operated alongside those that are included in the standard. Blau-Metall manufactures these non-standard sieves according to tolerances that have been derived from the aforementioned standards. This allows for a certification processes similar to that of standard sieves in order to provide full confidence by operators in the quality of these sieves and guarantee high reliability for a wealth of screening tasks requiring precision sieves not included in ISO 565.

Similarly, our Made-to-Spec sieves manufactured according to customer specifications and tolerances will receive Inspection Certificates 3.1 to demonstrate compliance with the specific requirements outlined for these purpose-built products.

Some Examples for Tolerances of non-standard Blau-Metall Sieves:
    • All sieves with slotted Apertures: Tolerance on Width (Δw1): ±0,05 mm, Length (Δw2): ±0,20 mm
    • 1,5 mm Round Apertures (Tolerance on Aperture Width: ±0,08 mm, Pitch: ±0,4 mm)
    • 3,0 mm Round Apertures (Tolerance on Aperture Width: ±0,11 mm, Pitch: ±0,65 mm)
    • 6,0 mm Round Apertures (Tolerance on Aperture Width: ±0,15 mm, Pitch: ±1,2 mm)
    • 7,0 mm Round Apertures (Tolerance on Aperture Width: ±0,17 mm, Pitch: ±1,3 mm)


The optical inspection and certification of non-standard sieves is completed according to the methods of the corresponding standard: