DIN 433 Flat Washers - ISO 7092 Flat Washers, Small Series, Product Class A

Flat washers defined in the DIN 433 standard published by the German Institute for Standardization (DIN) are designed as cheese head screws with a small outer diameter slightly smaller than standard flat washers. The nut has a single tab that can be bent to the side to prevent loosening. This standard consists of two parts:

• DIN 433-1 Product class A washers - Hardness up to 250 HV designed for use with cheese head screws
• DIN 433-2 Product class A washers - Hardness up to 300 HV designed for use with cheese head screws

Similarly, in the ISO 7092 standard published by the International Standards Organization (ISO), the characteristics of small series, product class A flat washers in hardness classes of 200 HV and 300 HV and nominal sizes ranging from 1,6 mm to 36 mm (nominal thread diameters) are described ( ISO 7092 Flat washers - Small series - Product class A).

Washers with a hardness class of 200 HV are suitable for:

• Cheese head screws in feature classes up to and including 8.8 or made of stainless steel
• Hex socket head screws in feature classes up to and including 8,8 or made of stainless steel
• Hex head screws in feature classes up to 8,8 or made of stainless steel
• Hardened scouring screws with cheese head

Washers of hardness class 300 HV are suitable for:

• Hex socket head screws in feature classes up to and including 10.9
• Hex head screws in feature classes up to and including 10.9

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

When soft material parts are compressed or large gaps are used in the workpiece, the user should check the technical suitability of this type of washer.

Our organization, among the numerous tests, measurements, analyses, and evaluations it provides for businesses in various sectors, also offers testing services for flat washers under the DIN 433 standard and for flat washers (small series, product class A ) under the ISO 7092 standard, with its trained and expert staff and advanced technological equipment.