Flat washer dimensions chart according to ASME B18.21.1-2009 standard. Flat washers from #0 to 3 inches nominal size with A and
B types are given in the chart.
Type A flat washers serve to minimize embedding and to help tightening. The
Type B flat washers fulfill the customary purpose of
distributing load over larger areas of lower strength
Some important notes from the ASME B18.21.1:
- Flat washers shall be made of low carbon steel, stainless steel, non-ferrous
metal, plastic, or other material as specified by the purchaser. The tolerances
given by the calculator are intended for metallic washers only.
- Hardened flat washers shall conform to the chemical and mechanical
requirements in ASTM F 436.
Note 1: Dimensions are in inches.
Note 2: Nominal flat washer sizes are intended for use with comparable nominal screw or bolt sizes.
Note 3: The 0.734-inch, 1.156-inch, and 1.469-inch outside diameters avoid washers which could be used in coin operated devices.
Note 4: Most part of the preferred sizes for Type A plain washers are from series previously designated “Standard Plate” and “SAE.” Where common sizes existed in
the two series, the SAE site is designated “N” (narrow) and the Standard Plate “W” (wide). These sizes as well as all other sizes of
Type A Plain Washers are to be ordered by I.D., O.D., and thickness dimensions.