Westfield Fasteners Product Specification:
DIN 9021 - Metric Form G Flat Washer
This product guide contains the specification for metric form G flat washers, a series of standard parts available from Westfield Fasteners. The basis of this specification is the DIN standard DIN 9021.
A large diameter washer where the external diameter is typically three times that of the nominal internal diameter. These washers are similar to those specified in BS 4320 form G.
Please note that due to manufacturing limitations, all nylon variants of these items are only "similar to" and not "in absolute accordance with" the standard specified.
Scope of the DIN standard.
DIN 9021 specifies the dimensions and tolerances for these larger sized washers with internal diameters from M2.5, up to and including M36. DIN 9021 covers carbon steel and stainless steel variants. For other materials, they are produced to the same dimensions as specified in this standard.
Table 1 below defines the overall dimensions and tolerances of this washer type.
Although the DIN 9021 standard has now been superceded by various ISO standards (including ISO 7093) off the shelf parts are more generally available to the older specification. The ISO standards specify the same dimensions and tolerances, but have revised hardness classes.
