GB/T 3098.26-2021 Active

This document specifies the mechanical and physical properties of flat washers used in bolted connections, made of carbon steel or alloy steel and conforming to the performance grades stipulated in GB/T 3098.1 and GB/T 3098.2, when tested under environmental temperatures of 10℃ to 35℃.
Note 1: These types of flat washers can also be used with other fasteners, such as self-tapping screws.
When tested under environmental temperatures of 10℃ to 35℃, flat washers that meet the requirements of this document may not be able to maintain the specified mechanical and physical properties at high or low temperatures.
Note 2: The applicable temperature range for flat washers that meet the requirements of this document is -50℃ to +150℃. When the operating temperature exceeds -50℃ to +150℃, or even up to +300℃, it is recommended that users consult relevant experts.
This document applies to flat washers and assembly parts made of carbon steel or alloy steel with a thickness of 0.2 mm to 12 mm, which conform to the following requirements:
——Flat washers (with or without patterns, ribs, or chamfers);
——Square flat washers;
——Flat washers with square holes;
——Special-shaped flat washers.
This document does not specify the following performance requirements:
——Corrosion resistance;
——Weldability.