3.1 This practice is provided to facilitate comparison of physical and mechanical properties of refractory materials by establishing uniform presentation of data.

3.2 Units have been chosen, where possible, to result in numbers of magnitude familiar in the refractories industry, that is, g/cm ³ rather than the SI preferred unit kg/m³. It is recommended that SI prefixes be selected for use with the units such that the resulting numerical values lie between 0.1 and 1000. For most properties, the prefixes kilo (k) and mega (M) are preferred. Other prefixes are given in the following table:

3.3 The conversion factors, which have been selected for their general utility in the refractories industry, have been taken from Standard E380, where possible. For uniformity, they have been presented to four decimal places. In use, the converted values should be rounded to the same number of significant figures as in the original value.

1.1 This practice presents the units to be employed for reporting the properties of refractories, such as density, crushing stress, modulus of rupture, tensile stress, thermal conductivity, and permeability.

1.2 For convenience, a table of conversion factors between inch-pound units and SI units is included.