These test methods cover the measurement of average grain size
and include the comparison procedure, the planimetric (or Jeffries)
procedure, and the intercept procedures. These test methods may
also be applied to nonmetallic materials with structures having
appearances similar to those of the metallic structures shown in
the comparison charts. These test methods apply chiefly to single
phase grain structures but they can be applied to determine the
average size of a particular type of grain structure in a
multiphase or multiconstituent specimen.
These test methods are used to determine the average grain size
of specimens with a unimodal distribution of grain areas,
diameters, or intercept lengths. These distributions are
approximately log normal. These test methods do not cover methods
to characterize the nature of these distributions. Characterization
of grain size in specimens with duplex grain size distributions is
described in Test Methods E1181. Measurement of individual, very
coarse grains in a fine grained matrix is described in Test Methods
These test methods deal only with determination of planar grain
size, that is, characterization of the twodimensional grain
sections revealed by the sectioning plane. Determination of spatial
grain size, that is, measurement of the size of the
three-dimensional grains in the specimen volume, is beyond the
scope of these test methods.
These test methods describe techniques performed manually using
either a standard series of graded chart images for the comparison
method or simple templates for the manual counting methods.
Utilization of semi-automatic digitizing tablets or automatic image
analyzers to measure grain size is described in Test Methods
These test methods deal only with the recommended test methods
and nothing in them should be construed as defining or establishing
limits of acceptability or fitness of purpose of the materials
The measured values are stated in SI units, which are regarded
as standard. Equivalent inch-pound values, when listed, are in
parentheses and may be approximate.
This standard does not purport to address all of the safety
concerns, if any, associated with its use. It is the responsibility
of the user of this standard to establish appropriate safety and
health practices and determine the applicability of regulatory
limitations prior to use.