Deutsches Institut fur Normung e. V.

Plain washers - Normal series - Product grade A (ISO 7089:2000); English version of
 N EN ISO 7089

Annotation

The International Standard specifies the characteristics of normal-series, product-grade-A plain washers in the 200 HV and 300 HV hardness classes and of nominal sizes (nominal thread diameters) ranging from 1.6 mm to 64 mm inclusive.

Washers of hardness class 200 HV are suitable for

hexagon bolts and screws of product grades A and B in property classes up to an including 8.8;

hexagon nuts of product grades A and B in property classes up to and including 8;

hexagon bolts, screws and nuts of stainless steel of seminar chemical composition;

case-hardened thread rolling screws.

Washers of hardness class 300 HV are suitable for

hexagon bolts and screws of product grades A and B in property classes up to and including 10.9;

hexagon nuts of product grades A and B in property classes up to and including 10.

If dimensions other than those listed in this International standard are required, they should be selected from those given in ISO 887.

When soft material pieces are clamped, or large clearance holes in the workpiece are used, the user should check the technical suitability of this type of washer.

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