ASME · ANSI / ASME B18.22.1

ANSI / ASME B 18.22.1 Standard: Technical Requirements for Plain Washers

Scope of the ANSI/ASME B 18.22.1 standard

This standard regulates the technical requirements for general-purpose plain washers, classifying them into Type A and Type B. This regulatory documentation defines the geometric parameters and tolerances necessary to ensure the reliability of threaded connections in various engineering structures.

EV Group China engineers note: the presence of a size in the standard does not guarantee its constant stock availability. To select the optimal fastener and clarify the production program, we recommend sending inquiries to our specialists.

Classification and functional purpose of washers

Type A. Washers of this category are historically divided into four series: light, medium, heavy, and extra-heavy. Their geometry is strictly correlated with the dimensions of bolt heads and nuts, which minimizes seating depth and simplifies the assembly process. When selecting products, one should focus on the preferred sizes presented in Table 1A. If the required size is not available, data from Table 1B may be used.

Type B. Type B washers are designed for general construction needs. They are available in narrow, regular, and wide executions. The main task of products in this group is the effective distribution of static load on the surfaces of materials with low load-bearing capacity. Selection is carried out according to the nominal diameter of the fastener shank, taking into account the required width of the contact area.

Technical tolerances and dimensional grid

All metric and imperial characteristics within the framework of this standard are given in inches, unless otherwise specified in the specific order specification.

Requirements for materials and heat treatment

For the production of washers, EV Group China uses a wide range of materials: from ferrous and non-ferrous metals to specialized polymers. The tolerances indicated in the tables are valid exclusively for metal products.

We supply solid stamped washers (without breaks) and coiled products with minimal gaps. Mechanical properties for hardened stamped washers comply with the ASTM A-325 specification. For wire-coiled washers, AISI 1060 steel is used, followed by thermal hardening to a hardness of 45-53 HRC on the Rockwell scale.

Quality control

All supplied products undergo strict inspection for the absence of burrs, sharp edges, surface defects, and traces of corrosion that could reduce the operational characteristics of the assembly.

Terminology

For the correct interpretation of technical terms and characteristics of fasteners within the framework of this standard, one should be guided by the ASA B18.12 glossary.