This Standard covers the dimensional requirements, physical properties, and related test methods for helical spring-lock washers (# 0 through 3 in.), tooth-lock washers (# 2 through 1 3⁄4 in.), and plain washers (# 0 through 3 in.).

The inclusion of dimensional data in this Standard is not intended to imply that all products described are stock production items. Consumers should consult with suppliers concerning the availability of products.

NOTE: The word lock appearing in the names of products in this Standard is a generic term historically associated with their identification and is not intended to imply an indefinite permanency of fixity in attachments where the fasteners are used.

ASME B18.21.1-2009 (R2016) is a revision and consolidation of ASME B18.21.1 and ASME B18.22.1.