ASTM D768-01(2019)

This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
Designation: D768 −01 (Reapproved 2019)
Standard Specification for
Yellow Iron Oxide Hydrated
This standard is issued under the fixed designation D768; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope
Total hydrated oxide of iron, min, % 93
A
Total oxide of iron, min, % 83
A
1.1 This specification covers the pigment commercially
Loss on ignition, max, % 13
Moisture and other volatile matter, max, % 1.0
known as yellow iron oxide, hydrated.
Water soluble matter, max, % 0.50
1.2 The values stated in SI units are to be regarded as the Coarse particles (total residue retained on a No. 325 0.5
(45-µm) sieve), max, %
standard. The values given in parentheses are for information
Hydrogen ion concentration (pH value) 4.5 to 8.0
only.
A
Total hydrated oxide of iron shall be the sum of iron oxide and loss on ignition.
1.3 This international standard was developed in accor-
Loss on ignition shall be calculated on the dry material.
dance with internationally recognized principles on standard-
ization established in the Decision on Principles for the
3.2 Paste in Oil—The paste in oil shall be made by
Development of International Standards, Guides and Recom-
thoroughly grinding the specified pigment with linseed oil
mendations issued by the World Trade Organization Technical
(with or without a small amount of volatile thinner) together
Barriers to Trade (TBT) Committee.
with (where necessary) small amounts of wetting or dispersing
agents to a semipaste or fluid type consistency. As received, it
2. Referenced Documents
shall not be caked in the container and shall break up readily in
2.1 ASTM Standards: oil to form a smooth paint of brushing consistency. It shall mix
D50 Test Methods for ChemicalAnalysis ofYellow, Orange, readily in all proportions, without curdling, with linseed oil,
Red, and Brown Pigments Containing Iron and Manga- turpentine, or volatile petroleum spirits, or any mixtures of
nese these substances. The paste shall conform to the following
D185 Test Methods for Coarse Particles in Pigments requirements:
D280 Test Methods for Hygroscopic Moisture (and Other
Pigment, min, % 55
Nonvolatile vehicle, min, % of vehicle 80
Matter Volatile Under the Test Conditions) in Pigments
Moisture by distillation, max, % 2.0
D1208 Test Methods for Common Properties of Certain
Coarse particles and skins (total residue retained on a 1.0
Pigments
No. 325 (45-µm) sieve), max, percent of the dry
pigment
Consistency by the Stormer viscometer:
3. Composition and Properties
A
At shearing rate of 100 revolutions/30 s, min, g 700
B
At shearing rate of 100 revolutions/35 s, max, g 1200
3.1 The pigment shall be a manufactured yellow iron oxide
obtained by chemical reaction. It shall be a soft, finely
A
Equivalent to a rating of 125 Krebs’ Units.
B
powdered pigment, free of admixtures of other substances and
Equivalent to a rating of 145 Krebs’ Units.
shall conform to the following requirements:
3.3 The mass color character of the tint and the tinting
strength formed by a mixture with a white pigment shall be
within mutual
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