ASTM B695-04(2016)

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
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Designation:B695 −04 (Reapproved 2016)
Standard Specification for
Coatings of Zinc Mechanically Deposited on Iron and Steel
This standard is issued under the fixed designation B695; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
This standard has been approved for use by agencies of the U.S. Department of Defense.
1. Scope A490Specification for Structural Bolts, Alloy Steel, Heat
Treated, 150 ksi Minimum Tensile Strength (Withdrawn
1.1 This specification covers the requirements for a coating
2016)
of zinc mechanically deposited on iron and steel basis metals.
A563Specification for Carbon and Alloy Steel Nuts
The coating is provided in several thicknesses up to and
B117Practice for Operating Salt Spray (Fog) Apparatus
including 107 µm. The seven thickest classes are usually
B183Practice for Preparation of Low-Carbon Steel for
referred to as “mechanically galvanized.”
Electroplating
1.2 This standard does not purport to address all of the
B242Guide for Preparation of High-Carbon Steel for Elec-
safety concerns, if any, associated with its use. It is the
troplating
responsibility of the user of this standard to establish appro-
B322Guide for Cleaning Metals Prior to Electroplating
priate safety and health practices and determine the applica-
B487Test Method for Measurement of Metal and Oxide
bility of regulatory limitations prior to use.
Coating Thickness by Microscopical Examination of
NOTE 1—The performance of this coating complies with the require- Cross Section
ments of Specification A153/A153M and MIL-C-81562.
B499Test Method for Measurement of CoatingThicknesses
by the Magnetic Method: Nonmagnetic Coatings on
1.3 The values stated in SI units are to be regarded as the
Magnetic Basis Metals
standard. The inch-pound equivalents of SI units are given for
B571Practice for Qualitative Adhesion Testing of Metallic
informational purposes.
Coatings
2. Referenced Documents B602Test Method for Attribute Sampling of Metallic and
Inorganic Coatings
2.1 ASTM Standards:
B697Guide for Selection of Sampling Plans for Inspection
A153/A153MSpecification for Zinc Coating (Hot-Dip) on
of Electrodeposited Metallic and Inorganic Coatings
Iron and Steel Hardware
B762Test Method of Variables Sampling of Metallic and
A194/A194MSpecification for Carbon Steel, Alloy Steel,
Inorganic Coatings
and Stainless Steel Nuts for Bolts for High Pressure or
F1470Practice for Fastener Sampling for Specified Me-
High Temperature Service, or Both
chanical Properties and Performance Inspection
A325Specification for Structural Bolts, Steel, Heat Treated,
2.2 Military Standard:
120/105 ksi Minimum Tensile Strength (Withdrawn
3 MIL-C-81562 Coating, Cadmium, Tin Cadmium and Zinc
2016)
(Mechanically Deposited)
2.3 AISC Standard:
Specifications for Structural Joints Using ASTM A325 or
This specification is under the jurisdiction of ASTM Committee B08 on
A490 Bolts
Metallic and Inorganic Coatings and is the direct responsibility of Subcommittee
B08.06 on Soft Metals.
3. Classification
Current edition approved Nov. 1, 2016. Published November 2016. Originally
approvedin1982.Lastpreviouseditionapprovedin2009asB695–04(2009).DOI:
3.1 Classes—Zinc coatings are classified on the basis of
10.1520/B0695-04R16.
thickness, as follows:
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
Standards volume information, refer to the standard’s Document Summary page on Available from Standardization Documents Order Desk, DODSSP, Bldg. 4,
the ASTM website. Section D, 700 Robbins Ave., Philadelphia, PA 19111-5098
3 5
The last approved version of this historical standard is referenced on Available from American Institute of Steel Construction (AISC), One E.
www.astm.org. Wacker Dr., Suite 700, Chicago, IL 60601-2001, http://www.aisc.org.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
B695−04 (2016)
6.2.1 Stress-Relief Treatment—All steel parts that have an
Class Minimum Thickness, µm
110 107
ultimate tensile strength of 1000 MPa and above and that
80 81
contain tensile stresses caused by machining, grinding,
70 69
straightening, or cold-forming operation shall be given a
65 66
55 53
stress-relief heat treatment prior to cleaning and metal deposi-
50 50
tion. The temperature and time at temperature shall be 190 6
40 40
15°C for a minimum of3hso that maximum stress relief is
25 25
12 12
obtained without reducing the hardness below the specified
minimum.
6.2.2 High-strength steels (which become embrittled when
3.2 Types—Zinccoatingsareidentifiedbytypesonthebasis
charged with hydrogen) and that have heavy oxide or scale
of supplementary treatment required, as follows:
shallbecleanedbeforeapplicationofthecoatinginaccordance
Type I—As coated, without supplementary treatment (Ap-
with Practice B242. In general, nonelectrolytic alkaline,
pendix X2.1).
anodic-alkaline, and some inhibited acid cleaners are preferred
Type II—With colored chromate conversion treatment (Ap-
toavoidtheriskofproducinghydrogenembrittlementfromthe
pendix X2.2).
cleaning procedure.
4. Ordering Information 6.2.3 For low-carbon steels, see Practice B183. Useful
guidelines are also given in Guide B322.
4.1 Supplyingthefollowinginformationbythepurchaserto
6.2.4 Mechanical deposition of zinc coatings shall consist,
the seller in the purchase order or other governing document
in general, of all of the steps listed below, and in the sequence
will make the application of this specification complete:
as shown:
4.1.1 Class, including a maximum thickness, if appropriate,
6.2.4.1 Preparation of the surface of the parts to be coated,
type,andforTypeII,colorandneedforsupplementallubricant
by chemical (generally acidic) procedure to an extent that
(3.1, 3.2, and 6.2.5),
permits uniformly satisfactory results from subsequent steps.
4.1.2 Nature of substrate (for example, high-strength steel),
6.2.4.2 Deposition of a thin metal coating, generally of
need for stress relief (6.2.1), and cleaning precautions to be
copper, by immersion in appropriate chemical solutions, with-
followed (6.2.2 and 6.2.3),
out the use of electric current. There are no thickness require-
4.1.3 Significant surfaces (6.3),
ments for this coating.
4.1.4 Requirements for and methods of testing for one or
6.2.4.3 Tumblingofthepartsthathavebeentreatedaccord-
more of the following, if required: need for and type of test
ing to 6.2.4.1 and 6.2.4.2 in a container with the following:
specimens (8.1), thickness (6.3 and 8.3), adhesion (6.4 and
(1)The zinc metal to be deposited, in powder form;
8.4), corrosion resistance (6.5 and 8.5), absence of hydrogen
(2)Impact media, which includes glass, for example, or
embrittlement,andthewaitingperiodbeforetestingandtesting
other substances that are essentially inert to the chemicals of
loads (6.6 and 8.6),
the deposition process. The function of this media is to aid in
4.1.5 Inspection responsibility (Section 11) and sampling
providingmechanicalforcestodrivethemetalpowderontothe
plan for each inspection criterion (Section 7), and
substrate parts;
4.1.6 Requirements for certified report of test results (Sec-
(3)A “promoter” or “accelerator” which aids in the uni-
tion 10).
form deposition of the metal powder; and
5. Workmanship
(4)A liquid medium, generally water.
6.2.4.4 Separation of the parts from the solid and liquid
5.1 The coating shall be uniform in appearance and free of
blisters, pits, nodules, flaking, and other defects that are media.
capable of adversely affecting the function of the coating. The 6.2.4.5 Rinsing.
coating shall cover all surfaces as stated in 6.3 including roots
6.2.4.6 Drying.
of threads, thread peaks, corners, recesses, and edges. The
6.2.5 Supplementary Treatments:
coating shall not be stained or discolored throughout to an
6.2.5.1 Colored Chromate Conversion Treatments (Type
extent capable of adversely affecting appearance as a func-
II)—Colored chromate conversion treatment for Type II shall
tional requirement. However, superficial staining, that results
be done in a solution containing hexavalent chromium ions.
from rinsing or drying, and variations in color or luster shall
This solution shall produce a bright or semi-bright continuous,
not be cause for rejection.
smooth, protective film with a uniform color that is capable of
ranging from yellow through bronze and olive-drab to brown
NOTE 2—The nature of the mechanical plating process is such that
coatings characteristically will not be as smooth or as bright as some andblackandthatarecapableofbeingdyedtoadesiredcolor.
electroplated coatings.
Bright dips that do not contain salts that yield films containing
hexavalent chromium ions are precluded as treatments for
6. Requirements
producing Type II coatings.
6.1 Appearance—The coating as deposited shall have a
6.2.5.2 Waxes, lacquers, or other organic coatings are not
uniform silvery appearance, and a matte to medium-bright
prohibited from being used to improve lubricity, and the need
luster.
for them shall be supplied in the purchase order or other
6.2 Process: governing document (see 4.1.1). Supplemental lubrication
B695−04 (2016)
is an inherent characteristic of mechanical deposition processes.
treatments shall not be used to ensure conformance to the salt
Therefore, the coating thickness will have to exceed the specified value at
spray corrosion resistance requirements (see 8.5.4).
some points on the significant surfaces to ensure that the thickness equals
6.2.5.3 Lubrication of grade DH nuts processed in accor-
or exceeds the specified value at all points. Hence, in most cases, the
dancewiththisspecificationandusedwithSpecificationA325
average coating thickness on an article will be greater than the specified
high-strength bolts is a requirement of paragraph 6.5 of value; how much greater is largely determined by the shape of the article
and the characteristics of the deposition process.
Specification A325 and paragraph 4.8 of Specification A563.
In addition, the average coating thickness on articles will vary from
article to article within a production lot. Therefore, if all of the articles in
NOTE 3—Although not included in Specification A194/A194M, this
provision should apply to mechanically galvanized Specification A194/ aproductionlotaretomeetthethicknessrequirement,theaveragecoating
thicknessfortheproductionlotasawholewillbegreaterthantheaverage
A194M 2H nuts when supplied for use with Specification A325 bolts.
necessary to ensure that a single article meets the requirement.
NOTE4—SpecificationsforstructuraljointsusingSpecificationA325or
A490 bolts references the use of lubricants on nuts to be used with
6.4 Adhesion—The zinc coating shall be sufficiently adher-
SpecificationA325high-strengthboltsandisfoundinthecommentaryon
ent to the basis metal to pass the tests specified in 8.4.
this RCSC (Research Council on Structural Connections of the Engineer-
ing Foundation) Specification, within the paragraphs entitled “Effect Of
6.5 Corrosion Resistance:
Galvanizing Upon Torque Involved In Tightening” and “Shipping Re-
6.5.1 The presence of corrosion products visible to the
quirements For Galvanized Bolts and Nuts,” published November 1985,
5 unaided eye at normal reading distance at the end of the
page 30.
specified test periods stated in Table 1 shall constitute failure,
6.2.6 Surface Defects—Defects and variations in appear-
except that corrosion products at edges of specimens shall not
ance in the coating that arise from surface conditions of the
constitute failure. Slight “whisps” of white corrosion, as
substrate(scratches,pores,rollmarks,inclusions,etc.)andthat
opposed to obvious accumulations, shall be acceptable.
persist in the finish despite the observance of good metal
NOTE 8—Mechanical deposition is exclusively a barrel-finishing pro-
finishing practices shall not be cause for rejection.
cess. It is recognized that mechanical deposition on parts may therefore
NOTE 5—Applied finishes generally perform better in service when the produce surfaces that have a different characteristic from those on parts
substrate over which they are applied is smooth and free of torn metal, that are finished exclusively by racking. Similarly, corrosion testing of
inclusions, pores, and other defects. It is recommended that the specifi- actual parts may produce different results from those on test panels. Salt
cationscoveringtheunfinishedproductprovidelimitsforthesedefects.A spray requirements that are appropriate to indicate the technical quality
metal finisher can often remove defects through special treatments, such with which a process is carried out may be impractical for acceptance of
as grinding, polishing, abrasive blasting, chemical treatments, and elec- actualparts.Insuchcasesthepurchasershallindicatehisrequirementson
tropolishing. However, these are not normal in the treatment steps the purchase order (4.1.4).
preceding the application of the finish. When desired they must be NOTE 9—In many instances, there is no direct relation between the
specified on the purchase order (4.1.2). results of an accelerated corrosion test and the resistance to corrosion in
other media, because several factors that influence the progress of
6.3 Thickness:
corrosion, such as the formation of protective films, vary greatly with the
6.3.1 The thickness of the coating everywhere on the
conditions encountered. The results obtained in the test should not,
therefore, be regarded as a direct guide to the corrosion resistance of the
significant surfaces shall be at least that of the specified class
tested materials in all environments where these materials may be used.
as defined in 3.1.
Also,performanceofdifferentmaterialsinthetestcannotalwaysbetaken
6.3.2 Significant surfaces are defined as those normally
as a direct guide to the relative corrosion resistance of these materials in
visible (directly or by reflection) that are essential to the
service.
appearance or serviceability of the article when assembled in
6.5.2 On parts with Type II coatings, the greater number of
normal position; or that are capable of providing the source of
hours for either white corrosion products or rust shall apply.
corrosion products that deface visible surfaces on the as-
For example, for Type II, Class 8, the test shall be continued
sembled article. When necessary, the significant surfaces shall
until the 72-h requirement is met for white corrosion products;
be indicated on the
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